[原创]如何控制TreeView在打开的时候只展开两层？

树的Html代码如下：

 1 < iewc:TreeView  id ="TreeView1"  style ="Z-INDEX: 101; LEFT: 320px; POSITION: absolute; TOP: 160px"
 2                 runat ="server" >
 3                  < iewc:TreeNode  Text ="Node0" >
 4                      < iewc:TreeNode  Text ="Node3" >
 5                          < iewc:TreeNode  Text ="Node9" >
 6                              < iewc:TreeNode  Text ="Node0" ></ iewc:TreeNode >
 7                              < iewc:TreeNode  Text ="Node1" ></ iewc:TreeNode >
 8                          </ iewc:TreeNode >
 9                          < iewc:TreeNode  Text ="Node10" >
10                              < iewc:TreeNode  Text ="Node2" ></ iewc:TreeNode >
11                              < iewc:TreeNode  Text ="Node3" ></ iewc:TreeNode >
12                          </ iewc:TreeNode >
13                      </ iewc:TreeNode >
14                      < iewc:TreeNode  Text ="Node4" ></ iewc:TreeNode >
15                  </ iewc:TreeNode >
16                  < iewc:TreeNode  Text ="Node1" >
17                      < iewc:TreeNode  Text ="Node5" >
18                          < iewc:TreeNode  Text ="Node11" >
19                              < iewc:TreeNode  Text ="Node4" ></ iewc:TreeNode >
20                              < iewc:TreeNode  Text ="Node5" ></ iewc:TreeNode >
21                          </ iewc:TreeNode >
22                          < iewc:TreeNode  Text ="Node12" ></ iewc:TreeNode >
23                      </ iewc:TreeNode >
24                      < iewc:TreeNode  Text ="Node6" ></ iewc:TreeNode >
25                  </ iewc:TreeNode >
26                  < iewc:TreeNode  Text ="Node2" >
27                      < iewc:TreeNode  Text ="Node7" >
28                          < iewc:TreeNode  Text ="Node13" >
29                              < iewc:TreeNode  Text ="Node6" ></ iewc:TreeNode >
30                              < iewc:TreeNode  Text ="Node7" ></ iewc:TreeNode >
31                          </ iewc:TreeNode >
32                          < iewc:TreeNode  Text ="Node14" ></ iewc:TreeNode >
33                      </ iewc:TreeNode >
34                      < iewc:TreeNode  Text ="Node8" ></ iewc:TreeNode >
35                  </ iewc:TreeNode >
36              </ iewc:TreeView >

别忘了在窗体的onload事件中调用 ExpandOneTwo()函数

< body  MS_POSITIONING ="GridLayout"  onload ="ExpandOneTwo();" >

第1种非递归的方法：

 1   function  ExpandOneTwo()
 2          {
 3         
 4              var  NodeArray = new  Array();
 5             NodeArray = TreeView1.getChildren();
 6              for (i = 0 ;i < NodeArray.length;i ++ )
 7             {
 8                 cNode = NodeArray[i];
 9                 cNode.setAttribute( " expanded " , " true " );
10                  // alert(cNode.getAttribute("Text"));
11                  var  cNodeArray = new  Array();
12                 cNodeArray = cNode.getChildren();
13                  for (j = 0 ;j < cNodeArray.length;j ++ )
14                 {
15                   var  ccNode = cNodeArray[j];
16                   ccNode.setAttribute( " expanded " , " true " );
17                 }
18             }
19          }
20

第2种递归的方法：

 1 < script language = " javascript " >
 2         
 3           function  ExpandOneTwo()
 4          {
 5           // alert(arguments[0]);
 6             
 7              var  c = arguments[ 0 ];
 8              var  NodeArray = new  Array();
 9              if  (c == null )
10             {
11                 NodeArray = TreeView1.getChildren();
12                 
13                  if  (NodeArray != null )    
14                  for ( var  i = 0 ;i < NodeArray.length;i ++ )
15                 {    
16                     cNode = NodeArray[i];
17                     cNode.setAttribute( " expanded " , " true " );
18                      if  ((cNode.getParent() != null )  &&  (cNode.getParent().getParent() == null ))
19                      return ;
20                     ExpandOneTwo(cNode);      
21                 }
22             }
23              else
24             {
25                
26                 NodeArray = c.getChildren();
27                  if  (NodeArray != null )    
28                  for ( var  i = 0 ;i < NodeArray.length;i ++ )
29                 {    
30                     cNode = NodeArray[i];
31                     cNode.setAttribute( " expanded " , " true " );
32                      if  ((cNode.getParent() != null )  &&  (cNode.getParent().getParent() == null ))
33                      return ;
34                     ExpandOneTwo(cNode);      
35                 }
36             }
37             
38             
39          }
40          </ script >