前端框架Aurelia - Class & Style

1.Class

You can bind a css string or object to an element's 

style

 attribute.Use the 

style

 attribute'salias, 

css

 whendoing string interpolation to ensure your application is compatible with Internet Explorer and Edge.You can bind an element's 

class

 attributeusing string interpolation or with 

.bind

/

.one-time

.可以用字符串插值或者.bind/.one-time绑定元素的class属性。

<template>
<div class="foo ${isActive ? 'active' : ''} bar"></div>
<div class.bind="isActive ? 'active' : ''"></div>
<div class.one-time="isActive ? 'active' : ''"></div>
</template>

Toensure maximum interoperability with other JavaScript libraries, the binding system will only add or remove classes specified in the binding expression. This ensures classes added by other code (eg via 

classList.add(...)

)are preserved. This "safe by default" behavior comes at a small cost but can be noticeable in benchmarks or other performance critical situations like repeats with lots of elements. You can opt out of the default behavior by binding directly to the element's className propertyusing 

class-name.bind="...."

 or 

class-name.one-time="..."

.This will be marginally faster but can add up over a lot of bindings.为了兼容其它的库，也可以用classList.add(...)添加class。这是default添加class的方法。也可以选择不用default方法，用

class-name.bind="...."

 or 

class-name.one-time="..."来添加多个绑定的class。

2.Style

You can bind a css string or object to an element's 

style

 attribute.Use the 

style

 attribute'salias, 

css

 whendoing string interpolation to ensure your application is compatible with Internet Explorer and Edge.可以绑定一个css string变量或者一个object到元素的style属性上。用style的别名。直接用字符串插值添加style属性的时候，不要用style=“”而要用css=""，保证兼容。

export class StyleData {styleString: string;styleObject: any;constructor() {this.styleString = 'color: red; background-color: blue';this.styleObject = {color: 'red','background-color': 'blue'};}}

<template><div style.bind="styleString"></div><div style.bind="styleObject"></div></template>

illegal的字符串插值：

<template><div style="width: ${width}px; height: ${height}px;"></div></template>

合法的字符串插值：

<template><div css="width: ${width}px; height: ${height}px;"></div></template>