Hi!

I use a TreeView as sort of a Explorer Tree (I show Folders and Documents there).

If i click on a item, the OnSelectedNodeChanged is fired and i fill up a GridView with the correct data.

 So far so good.

Now to my question(s):

- Is there any chance to get the OnSelectedNodeChanged, if the already selected node is clicked?

- Can i deactivate the hyperlink of the currently selected node (means the user cannot click on the selected item anymore)?

Thanks for every hint.

Regards,

Christoph Unfried
 

Hi c.unfried,

The answer to both of your questions above is yes but you will have to make that happen:

1) To accomplish the first functionality, try the following:

    a)put a hidden variable in your page having the treeview( with id="Tree1", say) as:

           <input type="hidden" id="hdnTvSelNodeText" runat="server"/>

    b)put the below code inside your head tag in .aspx

      <script type="text/javascript">
            window.onload = function(){

             var treeview = document.getElementById("<%=Tree1.ClientID %>");
             var treeLinks = treeview.getElementsByTagName("a");
             for(i=0;i<treeLinks.length;i++)
                 {
                      if(treeLinks[i].firstChild.tagName != "IMG")
                          {
                                            
                              treeLinks[i].onclick =function(){
           
                                       document.getElementById("<%=hdnTvSelNodeId.ClientID%>").value = this.innerText;
                                   }
                          }
                  }
    }

   c)put the following code in your page  load as:

       protected void Page_Load(object sender, EventArgs e)
           {
                if (Tree1.SelectedNode != null && Tree1.SelectedNode.Text == hdnTvSelNodeId.Value)
                    {
                        Tree1_SelectedNodeChanged(sender, e); //this is the event handler for the OnSelectedNodeChanged event
                    }

 That's all for this case.

2)For the solution to the second problem:

     a)put a hidden variable in your page having the treeview( with id="Tree1", say) as:

           <input type="hidden" id="hdnTvSelNodeText" runat="server"/>

       b)put the below code inside your head tag in .aspx

      <script type="text/javascript">
            window.onload = function(){

             var treeview = document.getElementById("<%=Tree1.ClientID %>");
             var treeLinks = treeview.getElementsByTagName("a");
             for(i=0;i<treeLinks.length;i++)
                 {
                      if(treeLinks[i].firstChild.tagName != "IMG")
                          {

                                if(document.getElementById("<%=hdnTvSelNodeId.ClientID%>").value == treeLinks[i].innerText)
                                   {
                                        treeLinks[i].setAttribute("href","javascript:void(0);");
                                   }
                                            
                              treeLinks[i].onclick =function(){
           
                                       document.getElementById("<%=hdnTvSelNodeId.ClientID%>").value = this.innerText;
                                   }
                          }
                  }
    }

That's all for the second case.

Note that above two cases are mutually exclusive.

Hope this helps.

cheers!! 

Thank you for great answer.

It inspired me to my solution for this problem.

The name of each node is not unique in my case, that's why i decided to add a little javascript to my currently selected Treenode. This javascript sets a hidden Field.

 
Here is the code of my solution, which works for me:

.ASPX:

<asp:HiddenField ID="ExplorerTreeSelectedClicked" Value="false" runat="server" />

 .ASPX.cs:

protected void Page_Load(object sender, EventArgs e)
{

                InjectLoadEvent();
                if (ExplorerTreeSelectedClicked.Value == "true")
                {
                    // this is my Selected event method
                    ExplorerTree_Selected(sender, e);
                    ExplorerTreeSelectedClicked.Value = "false";
                }
} 

  private void InjectLoadEvent()
        {
            string javaScript =
                "var elem = document.getElementById('" + ExplorerTree.ClientID + "_SelectedNode');\n" +
                "if(elem != null && elem.value != '')\n" +
                "{\n" +
                "  var selectedNode = document.getElementById(elem.value);\n" +
                "  var newOnClick = selectedNode.getAttribute('onclick');\n" +
                "  newOnClick += 'document.getElementById(\\'" + ExplorerTreeSelectedClicked.ClientID + "\\').value=true';\n" +
                "  selectedNode.setAttribute('onclick', newOnClick);\n" +
                "}\n";

            Page.ClientScript.RegisterStartupScript(this.GetType(), "LoadEvent", javaScript, true);
        }