学习tree 控件（基础）

学习tree 控件：http://www.cxseo.net/web/200903/20/news_contentrid229.html

一、树形控件的常用属性

<wbr><wbr><wbr><wbr><wbr><span></span>1、dragMoveEnabled：是否在拖放的过程中将节点移动，而不是复制。</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>2、folderOpenIcon：展开节点时的节点图标</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>3、folderClosedIcon：关闭节点时的节点图标</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>4、defaultLeafIcon：叶子节点的图标</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>5、openItems：在初始化时展开的节点集。</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>6、showRoot：是否显示数据中的根节点。XML格式的数据一般包含根节点，此时该属性应为false；Array类型的数据一般不包含根节点，该属性设置无效。</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>7、indentation：节点层次缩进量。</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>8、doubleClickEnabled：节点是否支持双击事件。</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>9、dragEnabled：是否允许拖动节点。</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>10、dropEnabled：在拖动节点的过程中是否允许释放，以移动节点。</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>11、alternatingItemColors：节点间隔背景色。</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>12、<strong style="font-weight:bold"><span style="color:#0000ff; line-height:21px; word-break:normal; word-wrap:normal">labelField</span></strong>：作为标签显示的数据的属性。</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>13、<span style="color:#3300ff; line-height:21px; word-break:normal; word-wrap:normal"><strong style="font-weight:bold">labelFunction</strong></span>：自定义节点标签。</wbr></wbr></wbr></wbr></wbr>

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二、树形控件的常用事件

<wbr><wbr><wbr><wbr><wbr><span></span>1、itemClick：单击节点触发该事件。</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><span></span>2、itemDoubleClick：双击节点触发该事件。</wbr></wbr></wbr></wbr></wbr>

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使用XMLLISTCOLLECTION 和ARRAYCOLLECTION对象的对比。

你也许想知道，在运行时从远程或本地得来的数据被动态修改的时候，应该使用XMLListCollection对象还是ArrayCollection对象作为Tree空间的数据提供者。

如果你使用的数据源提供成形的XML，并且，你想在Tree控件中操作 XML数据。你应该使用XMLListCollection对象作为数据提供者。当使用MXML标记时，如果数据源是XMLList对象，你应该把它绑定到XMLLsitCollection对象的source属性上，然后把 XMLListCollection对象绑定到Tree控件的dataProvider属性上。

当你想要动态改变对象值时，不要使用XMLList或XML对象直接绑定到Tree控件的dataProvider属性上。当数据源是RPC(远程过程调用)服务的lastResult属性，并且你想使用XML数据，确保RPC组件的resultFormat属性被设置成e4x，当你使用e4x结果格式，最总结果就是XMLList，可以绑定在XMLListCollection对象上。

这里有一个例子。为例数据被动态改变，使用ArrayCollection对象作为Tree控件的数据提供器。当使用MXML标记时，如果你期望动态的改变Arrayl，你不应该把Array对象直接绑定到Tree控件的dataProvider属性上。作为代替，你应该绑定Array到一个ArrayCollection对象的source属性上，然后再把ArrayCollection对象绑定到Tree控件的dataProvider属性上。

当数据源是RPC(远程过程调用)服务的lastResult对象，并且RPC组件的resultFormat属性被成object，你应该使用ArrayUtil.toArray()方法来确保对象是一个Array。然后绑定到ArrayCollection对象上，就像下边的例子所示：

<mx:ArrayCollection
<wbr><wbr><wbr><span></span>id="employeeAC"<br><wbr><wbr><wbr><span></span>source= "{ArrayUtil.toArray(employeeSrv.lastResult.employees.employee)}"/&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

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例如1：

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" viewSourceURL="src/index.html">
<wbr><wbr><br><wbr><wbr><wbr><span></span>&lt;mx:Script&gt;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>&lt;![CDATA[ <wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>import mx.collections.XMLListCollection; <wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>[Bindable]<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>private var company:XML =<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>&lt;list&gt;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>&lt;department title="Finance" code="200"&gt;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>&lt;employee name="John H"/&gt;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>&lt;employee name="Sam K"/&gt;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>&lt;/department&gt;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>&lt;department title="Operations" code="400"&gt;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>&lt;employee name="Bill C"/&gt;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>&lt;employee name="Jill W"/&gt;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>&lt;/department&gt; <wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><span></span>&lt;department title="Engineering" code="300"&gt;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>