Distinguishing the Source Control of RadContextMenu

Environment

Product Version	2018.1 220
Product	RadContextMenu for WinForms

Description

The RadContextMenuManager component allows a single RadContextMenu instance to be associated with various controls. This KB article demonstrates a way to distinguish the source control of the menu. It may be useful in a scenario requiring the menu items need to be dynamically changed or different actions be invoked upon clicking the menu items. The example assumes that two different RadListView controls are using the same RadContextMenu. Additional information about the RadContextMenuManager component is available here: https://docs.telerik.com/devtools/winforms/menus/contextmenu/assign-radcontextmenu-to-telerik-and-non-telerik-controls.

Solution

The source control will be extracted from the element`s visual tree and stored in a variable so that it can be validated upon clicking the menu items.

Figure 1: Single Context Menu

Context Menu Events

• C#
• VB.NET

public partial class RadContextMenuSourceControlForm : Telerik.WinControls.UI.RadForm
{
    public RadContextMenuSourceControlForm()
    {
        InitializeComponent();
        this.radContextMenu1.DropDownOpening += RadContextMenu1_DropDownOpening;
        this.radMenuItem1.Click += RadMenuItem1_Click;
    }
    private void RadMenuItem1_Click(object sender, EventArgs e)
    {
        if (this.currentControl == this.radListView1)
        {
            //...
        }
        else if (this.currentControl == this.radListView2)
        {
            //...
        }
        RadMessageBox.Show(this.currentControl.Name);
    }
    RadControl currentControl = null;
    private void RadContextMenu1_DropDownOpening(object sender, CancelEventArgs e)
    {
        RadElement element = sender as RadElement;
        if (element == null)
        {
            return;
        }
        this.currentControl = element.ElementTree.Control as RadControl;
        if (this.currentControl != null)
        {
            Console.WriteLine(this.currentControl.Name);
        }
    }
}

Public Class RadContextMenuSourceControlForm
    Public Sub New()
        InitializeComponent()
        AddHandler Me.radContextMenu1.DropDownOpening, AddressOf RadContextMenu1_DropDownOpening
        AddHandler Me.radMenuItem1.Click, AddressOf RadMenuItem1_Click
    End Sub
    Private Sub RadMenuItem1_Click(ByVal sender As Object, ByVal e As EventArgs)
        If Me.currentControl Is Me.radListView1 Then
            '../
        ElseIf Me.currentControl Is Me.radListView2 Then
            '...
        End If
        RadMessageBox.Show(Me.currentControl.Name)
    End Sub
    Private currentControl As RadControl = Nothing
    Private Sub RadContextMenu1_DropDownOpening(ByVal sender As Object, ByVal e As CancelEventArgs)
        Dim element As RadElement = TryCast(sender, RadElement)
        If element Is Nothing Then
            Return
        End If
        Me.currentControl = TryCast(element.ElementTree.Control, RadControl)
        If Me.currentControl IsNot Nothing Then
            Console.WriteLine(Me.currentControl.Name)
        End If
    End Sub
End Class