How to: Support a Context Menu for a Custom WinForms List Editor

• Jun 11, 2021
• 2 minutes to read

In XAF applications, List Views can have context menus filled with Actions. For this purpose, the List Editor displaying a List View should support the IRequireContextMenu and IRequireDXMenuManager interfaces. This topic describes how to implement these interfaces in the WinCustomListEditor demonstrated in the How to: Implement a Custom WinForms List Editor topic.

The following image illustrates the context menu invoked for the WinCustomListEditor.

Note

You can see the code implemented here in the FeatureCenter demo installed with XAF. This demo is located in the %PUBLIC%\Documents\DevExpress Demos 24.2\Components\XAF\FeatureCenter.NETFramework.XPO folder by default.

To enable the context menu in a custom List Editor, modify its code in the following manner.

C#

[ListEditor(typeof(IPictureItem))]
public class WinCustomListEditor : ListEditor, /* ...*/ IRequireContextMenu, IRequireDXMenuManager {
    #region IRequireContextMenu Members
    private void BarManager_QueryShowPopupMenu(object sender, QueryShowPopupMenuEventArgs e) {
        if (e.Control != control) {
            e.Cancel = true;
            e.BreakShowPopupMenu = false;
        }
    }
    public void SetMenu(PopupMenu popupMenu, BarManager barManager) {
        barManager.SetPopupContextMenu(control, popupMenu);
        barManager.QueryShowPopupMenu += BarManager_QueryShowPopupMenu;
    }
        #endregion

        #region IRequireDXMenuManager Members
        public void SetMenuManager(IDXMenuManager menuManager) { }
        #endregion
}

VB.NET

<ListEditor(GetType(IPictureItem))> _
Public Class WinCustomListEditor ' ...
    Inherits ListEditor
    Implements IRequireContextMenu, IRequireDXMenuManager

    #Region "IRequireContextMenu Members"
    Private Sub BarManager_QueryShowPopupMenu(ByVal sender As Object, ByVal e As QueryShowPopupMenuEventArgs)
        If e.Control <> control Then
            e.Cancel = True
            e.BreakShowPopupMenu = False
        End If
    End Sub
    Public Sub SetMenu(ByVal popupMenu As PopupMenu, ByVal barManager As BarManager)
        barManager.SetPopupContextMenu(control, popupMenu)
        AddHandler barManager.QueryShowPopupMenu, AddressOf BarManager_QueryShowPopupMenu
    End Sub
        #End Region

        #Region "IRequireDXMenuManager Members"
        Public Sub SetMenuManager(ByVal menuManager As IDXMenuManager)
        End Sub
        #End Region
End Class

If you implement a List Editor using a descendant of the EditorContainer control, initialize the EditorContainer.MenuManager property in the SetMenuManager method.

In the QueryShowPopupMenu event handler, you can specify whether or not to cancel showing the context menu for the current region of the control using the e.Cancel parameter. For instance, you can use the following logic for the GridView control.

C#

GridHitTest hitTest = gridView.CalcHitInfo(gridControl.PointToClient(e.Position)).HitTest;
e.Cancel = !(((hitTest == GridHitTest.Row) || 
    (hitTest == GridHitTest.RowCell) || (hitTest == GridHitTest.EmptyRow) || 
    (hitTest == GridHitTest.RowDetail) || (hitTest == GridHitTest.None)));

VB.NET

Dim hitTest As GridHitTest = gridView.CalcHitInfo(gridControl.PointToClient(e.Position)).HitTest
e.Cancel = Not(((hitTest Is GridHitTest.Row) OrElse _
    (hitTest Is GridHitTest.RowCell) OrElse (hitTest Is GridHitTest.EmptyRow) OrElse _
    (hitTest Is GridHitTest.RowDetail) OrElse (hitTest Is GridHitTest.None)))