iOS开发：UIWebView的使用

简介

UIWebView用于在App中嵌入网页内容，通常情况下是html格式的网页，也支持pdf, word等文档。

用法详解

我们来做一个简单的UIWebView来实现浏览网页的功能。

1、创建UIWebView

- (void)creatWebView {
self.webView = [[UIWebView alloc]initWithFrame:CGRectMake(0, 64, self.view.bounds.size.width, self.view.bounds.size.height - 64)];
self.webView.delegate = self;
[self.view addSubview:self.webView];
}

可以给webView设置一些属性：

self.webView.scrollView.bounces = NO;   //取消回弹效果
self.webView.scalesPageToFit = YES;     //自动缩放页面/适应屏幕
self.webView.dataDetectorTypes = UIDataDetectorTypePhoneNumber; //检测网页中的电话号码，点击可拨打

2、选择加载方式

webView加载网页有几种方式：

//通过NSURLRequest加载网络URL

- (void)loadNetworkUrl {
if (!self.url) {
self.url = @"http://3g.163.com/";
}
[self.webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:self.url]]];
}

//通过NSURLRequest加载本地资源

- (void)loadLocateUrl {
NSString * path = [[NSBundle mainBundle] pathForResource:@"Objective-C_百度百科.html" ofType:nil];
[self.webView loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:path]]];
}

//通过NSString加载本地资源

- (void)loadLocateString {
NSString * path = [[NSBundle mainBundle] pathForResource:@"万众科技有限公司_百度百科.html" ofType:nil];
NSString * StringOfHtml = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
[self.webView loadHTMLString:StringOfHtml baseURL:[NSURL URLWithString:path]];
}

3、实现代理方法

- (void)webViewDidStartLoad:(UIWebView *)webView {
NSLog(@"开始加载....");
}

- (void)webViewDidFinishLoad:(UIWebView *)webView {
NSLog(@"加载完成");

//显示标题
self.title = [self.webView stringByEvaluatingJavaScriptFromString:@"document.title"];
}

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
return YES;
}

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
NSLog(@"加载失败");

}

4、Optional：通过Nav跳转页面

如果需要通过Nav跳转来展示网页跳转的内容，则可以在webView: shouldStartLoadWithRequest: navigationType: 代理方法里面加入以下代码：

//获取点击的URL
NSString * clickURL = [NSString stringWithFormat:@"%@",request.URL];
NSLog(@"%@",clickURL);
//如果是点击链接操作，则使用Nav跳转
if (navigationType == UIWebViewNavigationTypeLinkClicked) {
WebViewController * VC = [[WebViewController alloc]init];
VC.loadingType = LoadingNetworkUrlWithNavJump;
VC.url = clickURL;
[self.navigationController pushViewController:VC animated:YES];
//return NO，不加载
return NO;
}
return YES;
}
//return NO，加载
return YES;

5、加入控制按钮

加入 < > o x 四个按钮来实现对网页的控制功能：

- (void)configControlBtns {
NSArray * btns = [NSArray arrayWithObjects:@"返回",@"前进",@"刷新",@"停止", nil];
int spacing = (self.view.bounds.size.width - btns.count * 50) / (btns.count + 1);
for (int i = 0; i < btns.count; i++) {
UIButton * button = [UIButton buttonWithType:UIButtonTypeSystem];
[button setFrame:CGRectMake( spacing * (i + 1) + 50 * i, self.view.bounds.size.height - 40, 50, 30)];
[button setTitle:btns[i] forState:UIControlStateNormal];
[button setBackgroundColor:[UIColor yellowColor]];
[button setTag:1000 + i];
[self.view addSubview:button];
[button addTarget:self action:@selector(dealClickAction:) forControlEvents:UIControlEventTouchUpInside];
}
}

- (void)dealClickAction:(UIButton *)button {
//控制按钮执行事件，这里没有加判断
switch (button.tag) {
case 1000:
[self.webView goBack];
break;
case 1001:
[self.webView goForward];
break;
case 1002:
[self.webView reload];
break;
case 1003:
[self.webView stopLoading];
break;
default:
break;
}
}

6、mission complete！

我们来看看效果：

7、demo下载

下载地址：[点击我] (https://github.com/DaMingShen/UIWebViewDemo)