Kendo UI开发教程(11): Kendo MVVM (二) ObservableObject 对象

矫情吗；* 2023-10-16 19:23 68阅读 0赞

#### 概述 ####

Kendo MVVM框架关键的一个部分为ViewModel，它主要是通过kendo.data.ObserableObject来提供支持的。它可以监控改变（UI变化或是值的变化）并通知关心该变化的组件。 本篇以下ViewModel 和 ObservableObject 代表同一对象。

为了创建一个ObservableObject 对象，可以通过创建一个新kendo.data.ObservableObject 实例或是使用`kendo.observable方法，这两种方法效果相同。`

例如：

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">1</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">var</code>&nbsp;<code style="">viewModel1 =&nbsp;</code><code style="">new</code>&nbsp;<code style="">kendo.data.ObservableObject( { </code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">2</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&nbsp;&nbsp;</code><code style="">field1:&nbsp;</code><code style="">"value1"</code><code style="">,</code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">3</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&nbsp;&nbsp;</code><code style="">field2:&nbsp;</code><code style="">"value2"</code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">6</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">var</code>&nbsp;<code style="">viewModel2 = kendo.observable( { </code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">7</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&nbsp;&nbsp;</code><code style="">field1:&nbsp;</code><code style="">"value1"</code><code style="">,</code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">8</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&nbsp;&nbsp;</code><code style="">field2:&nbsp;</code><code style="">"value2"</code></td> 
  </tr> 
 </tbody> 
</table>

kendo.bind 方法内部实现时自动将给定的ViewModel对象转换为一个ObservableObject 对象，除非传入的参数类型已经是一个ObservableObject 对象。

注：如果某个ViewModel对象在初始后以后还会使用到（在调用kendo.bind之前或之后），则必须使用kendo.observable方法或是new kendo.data.ObservableObject来创建一个ViewModel对象。比如：

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">1</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">var</code>&nbsp;<code style="">viewModel = kendo.observable({ </code></td> 
  </tr> 
 </tbody> 
</table>

如果ViewModel对象在初始化后不再访问这个对象，那么你可以使用普通的JavaScript对象，此时kendo.bind方法不会把原始的ViewMode对象转化为kendo.data.ObservableObject. 例如，下面的代码出错：

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">8</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">The following statement&nbsp; will fail because the View-Model</code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">11</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">viewModel.set(</code><code style="">"name"</code><code style="">,&nbsp;</code><code style="">"Jane Doe"</code><code style="">);</code></td> 
  </tr> 
 </tbody> 
</table>

因此强烈建议总是使用 kendo.observable 来初始化一个ViewModel对象。

#### 读取ObservableObject ####

使用get方法来读取ObservableObject对象的属性。例如：

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">1</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">var</code>&nbsp;<code style="">viewModel = kendo.observable({ </code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">6</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">alert(name);&nbsp;</code><code style="">// shows "John Doe"</code></td> 
  </tr> 
 </tbody> 
</table>

get也支持读取嵌套的属性，例如：

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">1</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">var</code>&nbsp;<code style="">viewModel = kendo.observable({ </code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">2</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&nbsp;</code><code style="">person: { </code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">6</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">var</code>&nbsp;<code style="">personName = viewModel.get(</code><code style="">"person.name"</code><code style="">);</code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">7</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">alert(personName);&nbsp;</code><code style="">// shows "John Doe"</code></td> 
  </tr> 
 </tbody> 
</table>

#### 设置ObservableObject属性 ####

使用set方法来设置ObservableObject属性，例如：

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">1</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">var</code>&nbsp;<code style="">viewModel = kendo.observable({ </code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">7</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">var</code>&nbsp;<code style="">name = viewModel.get(</code><code style="">"name"</code><code style="">);</code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">8</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">alert(name);&nbsp;</code><code style="">// shows "Jane Doe"</code></td> 
  </tr> 
 </tbody> 
</table>

同样，set也支持设置嵌套的属性，例如：

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">1</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">var</code>&nbsp;<code style="">viewModel = kendo.observable({ </code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">2</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&nbsp;</code><code style="">person: { </code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">7</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">viewModel.set(</code><code style="">"person.name"</code><code style="">,&nbsp;</code><code style="">"Jane Doe"</code><code style="">);</code></td> 
  </tr> 
 </tbody> 
</table>

#### 创建关联属性（或者成为计算后属性） ####

在应用中常常需要把某个ViewModel的属性重新格式成适合View显示的形式，在这种情况可以通过创建一个新的关联属性来实现，比如：

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">1</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&lt;span data-bind=</code><code style="">"text: fullName"</code><code style="">&gt;&lt;/span&gt;</code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">2</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&lt;script&gt;</code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">3</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">var</code>&nbsp;<code style="">viewModel = kendo.observable({ </code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">6</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&nbsp;&nbsp;&nbsp;&nbsp;</code><code style="">fullName:&nbsp;</code><code style="">function</code><code style="">() { </code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">7</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code style="">return</code>&nbsp;<code style="">this</code><code style="">.get(</code><code style="">"firstName"</code><code style="">) +&nbsp;</code><code style="">" "</code>&nbsp;<code style="">+&nbsp;</code><code style="">this</code><code style="">.get(</code><code style="">"lastName"</code><code style="">);</code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">11</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">kendo.bind($(</code><code style="">"span"</code><code style="">), viewModel);</code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">12</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&lt;/script&gt;</code></td> 
  </tr> 
 </tbody> 
</table>

在这个例子中fullName为一关联属性，它依赖于firstName和lastName， 使用set修改firstName或是LastName后，FullName的值也随之变化。

要注意的是fullName的实现，对firstName,和lastName的访问，是通过get方法来实现的，如果使用下面的方法：

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">1</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">var</code>&nbsp;<code style="">viewModel = kendo.observable({ </code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">2</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&nbsp;&nbsp;&nbsp;&nbsp;</code><code style="">firstName:&nbsp;</code><code style="">"John"</code><code style="">,</code></td> 
  </tr> 
 </tbody> 
</table>

<table style=""> 
 <tbody style=""> 
  <tr style=""> 
   <td style=""><code style="">3</code></td> 
   <td style="border-width:0px 0px 0px 3px!important; margin:0px!important; padding:0px 0px 0px 0.5em!important; outline:0px!important; left:auto!important; top:auto!important; width:auto!important; height:auto!important; right:auto!important; bottom:auto!important; color:rgb(185,189,182)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; font-variant:inherit; vertical-align:top!important; border-left-color:rgb(67,90,95)!important; border-left-style:solid!important; float:none!important; position:static!important; direction:ltr!important"> <code style="">&nbsp;&nbsp;&nbsp;&nbsp;</code><code style="">lastName:&nbsp;</code><code style="">"Doe"</code><code style="">,</code></td> 
  </tr> 
 </tbody> 
</table>

上面代码直接使用this.firstName来访问ObserableObject的属性，在这种情况下，fullName不会跟踪firstName和lastName的变化，此时改变firstName和lastName，fullName的值不变，因此建议总是使用get来访问某个属性。