Handling button click events in ITemplate object used for NodeTemplate

[Nicholas Cloud]

Hello, I have a custom ITemplate class that I am using to format the output of nodes in a RadTreeView.  In the template, I have several asp:Button objects.  I want to wire up the Click events of each, and handle them on the page with AJAX calls to server-side methods.  I have added event handlers for each button to the ITemplate object but as far as I can tell they never fire.  When I click the buttons on the page I get an error message that tells me that ViewState has failed to load, but nothing else happens.  Do I need to do anything special to the page in order to handle the events?

.aspx page markup

<telerik:RadAjaxManager ID="radAjaxManager" runat="server">
    <AjaxSettings>
        <telerik:AjaxSetting AjaxControlID="radOrgNodeTree">
            <UpdatedControls>
                <telerik:AjaxUpdatedControl ControlID="radOrgNodeTree" />
            </UpdatedControls>
        </telerik:AjaxSetting>
    </AjaxSettings>
</telerik:RadAjaxManager>

<telerik:RadTreeView ID="radOrgNodeTree" runat="server"
    AllowNodeEditing="false"
    OnClientLoad="tree.load"
    OnClientNodeClicking="tree.nodeClicking"
    OnClientNodeClicked="tree.nodeClicked"
    OnClientContextMenuShowing="tree.contextMenuShowing"
    OnClientMouseOver="tree.mouseOver"
    OnClientContextMenuItemClicked="tree.contextMenuItemClicked"
    >
    <ContextMenus>
        <telerik:RadTreeViewContextMenu
            ID="orgNodeContextMenu"
            runat="server"
            ClickToOpen="true"
            Skin="Vista">
            <Items>
                <telerik:RadMenuItem Text="Add New..." Value="add" />
                <telerik:RadMenuItem Text="Edit" Value="edit" />
                <telerik:RadMenuItem Text="Delete" Value="delete" />
                <telerik:RadMenuItem Text="Collapse All" Value="collapse" />
            </Items>
        </telerik:RadTreeViewContextMenu>
    </ContextMenus>
</telerik:RadTreeView>

code behind

protected void Page_Load(object sender, EventArgs e) {

if(!IsPostBack) {

TreeNodeTemplate treeNodeTemplate = new TreeNodeTemplate();

treeNodeTemplate.Command += treeNodeTemplate_Command;

radOrgNodeTree.NodeTemplate = treeNodeTemplate;

//set data source

}

radOrgNodeTree.DataBind();

}

private void treeNodeTemplate_Command(object sender, CommandEventArgs e) {

//...

}

template class

private class TreeNodeTemplate : ITemplate {

        public event CommandEventHandler Command;

        private void OnCommand(CommandEventArgs e) {

            if (Command != null) {
                Command(this, e);
            }
        }

        public void InstantiateIn(Control container) {
            //...

            Button saveButton = new Button();
            //set properties
            saveButton.Command += saveButton_Command;
            //data binding event handler
            //add to controls collection

            //...
        }

        private void saveButton_Command(object sender, CommandEventArgs e) {
            OnCommand(e);
        }
    }

[Peter]

Hi Nicholas,

Your code looks correct. We have used to to create a test page and everything worked fine. Please, download the attached sample and use it for reference. Note, that when adding controls in InstantiateIn, you have to specify the ID:

public void InstantiateIn(Control container)
  {
      //...
      Button saveButton = new Button();
      saveButton.ID = "saveButton1";
      saveButton.Text = "save";

      //set properties
      saveButton.Command += saveButton_Command;
      //data binding event handler
      //add to controls collection
      container.Controls.Add(saveButton);
      //...
  }

Could this be the missing piece of the puzzle?

Kind regards,
Peter
the Telerik team

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