Question

TreeNodeCheckChanged is not working in my ASP.Net application.

<asp:TreeView ID="TreeView1" ShowCheckBoxes="All" runat="server"                      
     OnTreeNodeCheckChanged="TreeView1_TreeNodeCheckChanged">
</asp:TreeView>

protected void Page_Load(object sender, EventArgs e)
{
   if (!this.Page.IsPostBack)
   {
      TreeView(); //bind manually
   }
}

How can I fix this ?

Answer 1

How are you binding your TreeView?

I guess you are binding on every Page_Load (or Page_Init, whatever) regardless of this.Page.IsPostback

If you rebind your TreeView before the EventHandler is reached in the Asp.net Lifecycle, you will suppress all events that should be raised, e.g. your OnTreeNodeCheckedChanged event

Only bind upon

if(!this.Page.IsPostBack)
{
  // insert your initial binding of your treeview here
}

Upon postbacks you have to rebind after the desired event handlers have been executed

---

Edit:
You need to manually force a PostBack, because the TreeView won’t fire a Postback changing the Checked property of the rendered checkboxes.

Even though the TreeNodeCheckChanged
event is fired on post back, changing
a check box does not cause a post
back.

TreeView.TreeNodeCheckChanged Event