TreeView问题!加载出现问题，有时候出现，有时候又不出现!请教高手

jemmy 2003-07-23 12:29:50

The node at index 0.0 is not currently displayed in the tree. SelectedNodeIndex cannot be set to an undisplayed node (all parents of a selected node must be expanded).
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.Exception: The node at index 0.0 is not currently displayed in the tree. SelectedNodeIndex cannot be set to an undisplayed node (all parents of a selected node must be expanded).

源错误:

执行当前 Web 请求期间生成了未处理的异常。可以使用下面的异常堆栈跟踪信息确定有关异常原因和发生位置的信息。

堆栈跟踪:

[Exception: The node at index 0.0 is not currently displayed in the tree. SelectedNodeIndex cannot be set to an undisplayed node (all parents of a selected node must be expanded).]
Microsoft.Web.UI.WebControls.TreeView.set_SelectedNodeIndex(String value)
Microsoft.Web.UI.WebControls.TreeView.DoSelectedIndexChange(TreeViewSelectEventArgs e)
Microsoft.Web.UI.WebControls.TreeView.ProcessEvents(String eventArg)
Microsoft.Web.UI.WebControls.TreeView.ProcessData(String strData)
Microsoft.Web.UI.WebControls.BasePostBackControl.LoadPostData(String postDataKey, NameValueCollection postCollection)
Microsoft.Web.UI.WebControls.BasePostBackControl.System.Web.UI.IPostBackDataHandler.LoadPostData(String postDataKey, NameValueCollection postCollection)
System.Web.UI.Page.ProcessPostData(NameValueCollection postData, Boolean fBeforeLoad)
System.Web.UI.Page.ProcessRequestMain()

代码如下：
/////////////////////////////////////////////////////////
private void show_tree()
{
Microsoft.Web.UI.WebControls.TreeNode rootnode=new Microsoft.Web.UI.WebControls.TreeNode();
rootnode.NodeData=this.rootid.ToString();
rootnode.Text=this.rootname;
rootnode.ImageUrl="images/tree/base.gif";
rootnode.ExpandedImageUrl="images/tree/base.gif";
this.show_tree_ChildNode(rootnode);
this.OrgTree.Nodes.Add(rootnode);
this.treecell.Controls.Add(this.OrgTree);
TreeSet();
}

private int show_tree_ChildNode(Microsoft.Web.UI.WebControls.TreeNode cur)
{
cur.Nodes.Clear();
string sql = "select orgid,orgname from bool_sys_org where parentid="+ cur.NodeData;
Conn getsubnodes=new Conn(sql,"select");
int tncount = 0;
while(getsubnodes.reader.Read())
{
tncount++;
Microsoft.Web.UI.WebControls.TreeNode subnode = new Microsoft.Web.UI.WebControls.TreeNode();
subnode.Text = (getsubnodes.reader.GetValue(1)).ToString();
subnode.NodeData = (getsubnodes.reader.GetValue(0)).ToString() ;
if (show_tree_ChildNode(subnode) > 0)
{
subnode.ExpandedImageUrl = "images/tree/folderopen.gif";
subnode.ImageUrl = "images/tree/folder.gif";
}
else
{
subnode.ImageUrl = "images/tree/folder.gif";
}
cur.Nodes.Add(subnode);
}
getsubnodes.CloseDatabase();
return tncount;
}

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