您的位置：首页 > 其它

Weex入门与进阶指南

2016-09-04 12:20 501 查看
版权声明：本文为博主原创文章，未经博主允许不得转载。http://blog.csdn.net/jasonblog/article/details/51863173

目录(?)[+]

原文地址：https://yq.aliyun.com/articles/57554

前言

相比较于React Native的“Learn once, write anywhere”，Weex的口号是“Write
once, run everywhere”。考虑到React Native比较任性的向下兼容性，我们也引入了Weex做一番了解。
本文主要分为以下几个部分：
构建Hello World程序；
集成到现有的iOS工程中；
使用Weex的高级特性；
如何为Weex做贡献；

一、Weex入门

1.1 Hello Weex

参考官方教程，我们需要先安装Node。在Mac上也可以通过Homebrew直接进行安装：
brew
install node
。
接着我们需要安装Weex CLI：
npm install -g weex-toolkit
，并确保版本号大于0.1.0：
<code class="hljs brainfuck has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">$</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">weex</span> <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">-</span><span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">-</span><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">version</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">info</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">0</span><span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">.</span><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">3</span><span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">.</span><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">4</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul>

至此，准备工作已经到位，我们可以开始编写Weex程序了。 

创建一个名为
helloweex.we
的文件，并编写以下代码：
<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">template</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">text</span>></span>Hello Weex<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">text</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">template</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>

通过命令行在
helloweex.we
文件所在的目录下执行如下命令：
<code class="hljs vhdl has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">$ weex helloweex.we
info Fri Jul <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">08</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2016</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">14</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">30</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31</span> GMT+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0800</span> (CST)WebSocket  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">is</span> listening <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">on</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">port</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8082</span>
info Fri Jul <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">08</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2016</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">14</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">30</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31</span> GMT+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0800</span> (CST)http  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">is</span> listening <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">on</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">port</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8081</span> </code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>

此时，浏览器会打开一个新的标签页展示
helloweex.we
的执行效果：



注意到此时地址栏的内容
http://127.0.0.1:8081/weex_tmp/h5_render/?hot-reload_controller&page=helloweex.js&loader=xhr
包含着
hot
reload
字样，所以可以自然联想到当我们在源文件做修改并保存后，该页面会自动刷新展示效果。

1.2 基础结构

上面的示例只是一个非常简单的雏形，而一个比较完整的Weex程序包括三个部分：模板（Template）、样式（Style）和脚本（Script）。
比如我们可以利用上文提到的
hot reload
，修改文本的颜色并实时查看效果：
<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">template</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">text</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"title"</span>></span>Hello Weex<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">text</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">template</span>></span>

<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">style</span>></span><span class="css" style="box-sizing: border-box;">
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.title</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>; <span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
</span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">style</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>




接着我们添加上第三组成部分：脚本（Script）：
<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">template</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">text</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"title"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">onclick</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"onClickTitle"</span>></span>Hello Weex<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">text</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">template</span>></span>

<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">style</span>></span><span class="css" style="box-sizing: border-box;">
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.title</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>; <span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
</span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">style</span>></span>

<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span><span class="javascript" style="box-sizing: border-box;">
module.exports = {
methods: {
onClickTitle: <span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">function</span> <span class="hljs-params" style="color: rgb(102, 0, 102); box-sizing: border-box;">(e)</span> {</span>
console.log(e);
alert(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'title clicked.'</span>);
}
}
}
</span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li></ul>

这样一来，当我们点击文本的时候会出现如下效果：



更多语法相关内容可以参考官方文档。

二、集成到iOS工程

2.1 概述

上面是从前端的角度来初步看Weex的基础效果，对于客户端来讲，这类框架的一个优势就是能够结合Native代码发挥作用。比如在人手紧张的情况下可以一次开发，然后应用在不同平台终端上。
所以，这里讨论下如何将其集成到现有的iOS工程项目当中。
参考官方文档，我们先从GitHub下载Weex源码。
解压后将目录下的
ios/sdk
复制到现有的iOS工程目录下，并根据相对路径更新既有工程的podfile，然后执行
pod
update
将Weex iOS SDK集成进既有的iOS项目中；
在iOS Native代码中初始化Weex SDK，然后创建出要展示Weex程序的ViewController，具体见如下描述；


2.2 在iOS应用上运行Weex程序

在如何集成的文档中，前面说的比较清楚，但是在
初始化Weex环境
和
渲染Weex实例
这两个小节中，可能是由于代码是从比较大的项目源码中摘录出来的，所以存在一些不必要或没有上下文的代码。
这里描述下在开发调试阶段运行Weex程序。


2.2.1 确定要运行的Weex程序

创建一个
WeexDebugViewController
，进行如下布局：



通过填入IP和文件名来定位我们要运行的Weex程序。此外，还可以结合
weex helloweex.we --qr -h {ip or hostname}
命令来生成二维码，进行扫描演示，不过解析二维码还是为了获取到Weex程序所在位置。

2.2.2 初始化Weex SDK

开发调试阶段我们可以先将Weex SDK的初始化放在这个
WeexDebugViewController
中：
<code class="hljs bash has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">- (void)initWeex {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
[WXAppConfiguration <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">set</span>AppGroup:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"AliApp"</span>];
[WXAppConfiguration <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">set</span>AppName:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"WeexDemo"</span>];
[WXAppConfiguration <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">set</span>AppVersion:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"1.0.0"</span>];

[WXSDKEngine initSDKEnviroment];

[WXLog <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">set</span>LogLevel:WXLogLevelVerbose];
});
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li></ul>


2.2.3 运行Weex程序的ViewController

点击
ShowWeex
按钮时，我们可以根据两个输入框的内容拼接出要运行的Weex程序的位置，然后将其赋值给用来渲染Weex实例的
WeexShowcaseViewController
：
<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)showWeex {
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> *str = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> stringWithFormat:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"http://%@:8081/%@"</span>, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.ipField</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.text</span>, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.filenameField</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.text</span>];
WeexShowcaseViewController *vc = [WeexShowcaseViewController new];
vc<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.weexUri</span> = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSURL</span> URLWithString:str];
[<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.navigationController</span> pushViewController:vc animated:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">YES</span>];
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>

接着我们来看看
WeexShowcaseViewController
的源码：
<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#import <span class="hljs-title" style="box-sizing: border-box;"><WeexSDK/WeexSDK.h></span></span>

<span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@interface</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">WeexShowcaseViewController</span> ()</span>

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@property</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">nonatomic</span>, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">strong</span>) WXSDKInstance *weexSDK;

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@end</span>

<span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@implementation</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">WeexShowcaseViewController</span></span>

- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)dealloc {
[_weexSDK destroyInstance];
}

- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)viewDidLoad {
[<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span> viewDidLoad];
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Do any additional setup after loading the view.</span>

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.weexSDK</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.viewController</span> = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.weexSDK</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.frame</span> = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.view</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.frame</span>;

[<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.weexSDK</span> renderWithURL:<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.weexUri</span>];

__<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">weak</span> typeof(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span>) weakSelf = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.weexSDK</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.onCreate</span> = ^(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UIView</span> *view) {
[weakSelf<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.view</span> addSubview:view];
};

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.weexSDK</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.renderFinish</span> = ^(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UIView</span> *view) {
;
};

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.weexSDK</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.onFailed</span> = ^(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSError</span> *error) {
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"weexSDK onFailed : %@\n"</span>, error);
};
}

- (WXSDKInstance *)weexSDK {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (!_weexSDK) {
_weexSDK = [WXSDKInstance new];
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> _weexSDK;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li></ul>

2.2.4 运行起来

回到终端上，切换到
helloweex.we
文件所在的目录，将Weex的dev server跑起来：
<code class="hljs livecodeserver has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">$ weex -s .
info Fri Jul <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">08</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2016</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">38</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">59</span> GMT+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0800</span> (CST)<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">http</span>  is listening <span class="hljs-command" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">on</span> <span class="hljs-title" style="box-sizing: border-box;">port</span> <span class="hljs-title" style="box-sizing: border-box;">8081</span> </span>
info we <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">file</span> <span class="hljs-operator" style="box-sizing: border-box;">in</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">local</span> path . will be transformer <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">to</span> JS bundle
please access <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">http</span>://<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">30.9</span><span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">.112</span><span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">.173</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8081</span>/ </code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>

然后在Native上填入对应的IP和程序文件名：





到此，将Weex集成到现有iOS工程中算初步告一段落。

三、Weex进阶

当集成工作完成后，会发觉现有功能不足以满足业务需求，所以Weex支持开发者做一些扩展。

3.1 实现Weex接口协议

之前的
helloweex.we
示例中只有一个文本元素，现在再添加一个图片元素：
<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">template</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">image</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"thumbnail"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">src</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"http://image.coolapk.com/apk_logo/2015/0817/257251_1439790718_385.png"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">image</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">text</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"title"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">onclick</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"onClickTitle"</span>></span>Hello Weex<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">text</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">template</span>></span>

<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">style</span>></span><span class="css" style="box-sizing: border-box;">
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.title</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>; <span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.thumbnail</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">100</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">height</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">100</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
</span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">style</span>></span>

<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span><span class="javascript" style="box-sizing: border-box;">
module.exports = {
methods: {
onClickTitle: <span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">function</span> <span class="hljs-params" style="color: rgb(102, 0, 102); box-sizing: border-box;">(e)</span> {</span>
console.log(e);
alert(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'title clicked.'</span>);
}
}
}
</span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li></ul>

然后再执行：
$ weex helloweex.we
来运行查看效果：



可以在浏览器里看到这次多了一张图片。但是如果是运行在Native端，图片则得不到展示：



这是由于Weex SDK没有提供图片下载能力，需要我们来实现。


3.2 实现图片下载协议
WXImgLoaderProtocol

这个基本可以参考官方文档来实现。


3.2.1 定义图片下载Handler

<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#import <span class="hljs-title" style="box-sizing: border-box;"><WeexSDK/WeexSDK.h></span></span>

<span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@interface</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">WeexImageDownloader</span> : <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">NSObject</span> <<span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">WXImgLoaderProtocol</span>></span>

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@end</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>

3.2.2 实现协议接口

这个类必须遵循
WXImgLoaderProtocol
协议，并实现该协议定义的接口：
<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#import <span class="hljs-title" style="box-sizing: border-box;">"WeexImageDownloader.h"</span></span>
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#import <span class="hljs-title" style="box-sizing: border-box;"><SDWebImage/SDWebImageManager.h></span></span>

<span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@implementation</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">WeexImageDownloader</span></span>

- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">id</span><WXImageOperationProtocol>)downloadImageWithURL:(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> *)url
imageFrame:(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">CGRect</span>)imageFrame
userInfo:(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSDictionary</span> *)options
completed:(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>(^)(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UIImage</span> *image,  <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSError</span> *error, <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">BOOL</span> finished))completedBlock {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">id</span><WXImageOperationProtocol>)[[SDWebImageManager sharedManager] downloadImageWithURL:[<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSURL</span> URLWithString:url] options:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> progress:^(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSInteger</span> receivedSize, <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSInteger</span> expectedSize) {
} completed:^(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UIImage</span> *image, <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSError</span> *error, SDImageCacheType cacheType, <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">BOOL</span> finished, <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSURL</span> *imageURL) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (completedBlock) {
completedBlock(image, error, finished);
}
}];
}

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@end</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li></ul>

3.2.3 注册Handler

<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-attr_selector" style="color: rgb(0, 136, 0); box-sizing: border-box;">[WXSDKEngine registerHandler:[WeexImageDownloader new]</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">withProtocol</span>:<span class="hljs-at_rule" style="box-sizing: border-box;">@<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protocol(WXImgLoaderProtocol)];</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

这样一来，再次运行程序就可以看到图片了：



这样设计的好处主要是考虑了不同App依赖的网络库或者图片下载缓存库不同，避免Weex强依赖于一些第三方库，遵循依赖抽象而不是具体的原则。
BTW，我个人感觉
Weex
缩写成
WX
，
WeexImageLoaderProtocol
缩写成
WXImgLoaderProtocol
，不是很好看。

3.2 自定义UI组件

如果Weex的内置标签不足以满足要求时，我们可以自定义Native组件，然后暴露给.we文件使用。
比如我们可以定义一个
WeexButton
，继承自
WXComponent
，然后将其注册进Weex
SDK：
<code class="hljs ruby has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">[<span class="hljs-constant" style="box-sizing: border-box;">WXSDKEngine</span> <span class="hljs-symbol" style="color: rgb(0, 102, 102); box-sizing: border-box;">registerComponent:</span>@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"weex-button"</span> <span class="hljs-symbol" style="color: rgb(0, 102, 102); box-sizing: border-box;">withClass:</span>[<span class="hljs-constant" style="box-sizing: border-box;">WeexButton</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span>]];</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

这样一来，我们就可以在.we文件中使用这个标签了：
<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">weex-button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">title</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"hello"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">weex-button</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

标签中的属性我们可以在初始化函数中获得：
<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">- (instancetype)initWithRef:(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> *)ref
type:(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span>*)type
styles:(nullable <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSDictionary</span> *)styles
attributes:(nullable <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSDictionary</span> *)attributes
events:(nullable <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> *)events
weexInstance:(WXSDKInstance *)weexInstance {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span> = [<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span> initWithRef:ref type:type styles:styles attributes:attributes events:events weexInstance:weexInstance];
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span>) {
_title = [WXConvert <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span>:attributes[@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"title"</span>]];
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span>;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li></ul>

通过这些属性，我们可以在组件生命周期中修改组件的样式，比如设置按钮的title：
<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)viewDidLoad {
[<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span> viewDidLoad];

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.innerButton</span> = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UIButton</span> buttonWithType:UIButtonTypeRoundedRect];
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.innerButton</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.frame</span> = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.view</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.bounds</span>;
[<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.view</span> addSubview:<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.innerButton</span>];
[<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.innerButton</span> setTitle:<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.title</span> forState:UIControlStateNormal];
[<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.innerButton</span> addTarget:<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span> action:<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@selector</span>(onButtonClick:) forControlEvents:UIControlEventTouchUpInside];
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>

3.3 自定义模块

除了UI组件之外，有些时候我们希望JS层面能够调用Native的一些功能，比如通过JS代码让Native打开一个特定的ViewController。这时候，我们可以自定义一个模块向JS层面暴露API：
<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@synthesize</span> weexInstance;

WX_EXPORT_METHOD(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@selector</span>(call:withParam:callback:))
- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)call:(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> *)api withParam:(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSDictionary</span> *)param callback:(WXModuleCallback)callback {</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>

注意点如下： 

1. 需要遵循
WXModuleProtocol
协议； 

2. 需要合成（
synthesize
）
weexInstance
属性； 

3. 使用
WX_EXPORT_METHOD
来暴露API； 

4. 使用
WXModuleCallback
进行回调；
完成以上编码后，向Weex SDK注册：
[WXSDKEngine registerModule:
，就可以在.we文件中使用了：
<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span><span class="javascript" style="box-sizing: border-box;">
module.exports = {
methods: {
onClickTitle: <span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">function</span> <span class="hljs-params" style="color: rgb(102, 0, 102); box-sizing: border-box;">(e)</span> {</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">var</span> mymodule = <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">require</span>(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'@weex-module/mymodule'</span>);
mymodule.call(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'api'</span>, {}, <span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">function</span><span class="hljs-params" style="color: rgb(102, 0, 102); box-sizing: border-box;">(ret)</span> {</span>
});
}
}
}
</span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">script</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul>

四、为Weex做贡献

由于Weex刚开源不久，如果开发者发现一些问题或者需要改善的地方，可以直接在GitHub上进行fork，修改完后提交Pull
Request。
内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理 点击这里给我发消息
标签： 
相关文章推荐
新的分享
章节导航