Extjs 动态选择树的节点

var deptUserData = [];
 <s:if test="deptUserData!=null">
 deptUserData=<s:property value="deptUserData"/>;
 </s:if>
 //参与者树
     var tree = new Ext.tree.TreePanel({
         id: 'tree',
         onlyLeafCheckable: true,// 只对叶子节点可选
         animate: false, // 动画效果
         rootVisible: false,
         autoScroll: true,
         disabled: false,
         width: 620,
         height: 300,
         //frame:true,
         border: true, // 边框
         lines:true,
         //checkModel: 'single',
         loader: new Ext.tree.TreeLoader({
            baseAttrs: {
                uiProvider: Ext.ux.TreeCheckNodeUI
            }
        }),
         renderTo:'assignTree',
        root: deptUserData
    });

     tree.getRootNode().on('load',function(rootNode){
      rootNode.expand();
       for(var i = 0;i < checkedUsers.length;i++){
         tree.getNodeById(checkedUsers[i]).getUI().checkbox.checked=true;
      }
    });

var deptUserData = [];
<s:if test="deptUserData!=null">
deptUserData=<s:property value="deptUserData"/>;
</s:if>
//参与者树
	var tree = new Ext.tree.TreePanel({
	    id: 'tree',
	    onlyLeafCheckable: true,// 只对叶子节点可选
        animate: false, // 动画效果
        rootVisible: false,
        autoScroll: true,
        disabled: false,
        width: 620,
        height: 300,
		//frame:true,
        border: true, // 边框
        lines:true,
        //checkModel: 'single',
        loader: new Ext.tree.TreeLoader({
			baseAttrs: {
			    uiProvider: Ext.ux.TreeCheckNodeUI
			}
		}),
	    renderTo:'assignTree',
	    root: deptUserData
	});

	tree.getRootNode().on('load',function(rootNode){    
	  rootNode.expand();   
	  for(var i = 0;i < checkedUsers.length;i++){  
	    tree.getNodeById(checkedUsers[i]).getUI().checkbox.checked=true;   
	  }   
	});