How to: Add custom menu items to the standard menus

• Nov 28, 2019
• 3 minutes to read

How to: Display a Command that Clears Summaries in the Footer

The following example demonstrates how to add a custom item to a standard context menu and handle the click event for this item. The TreeList.PopupMenuShowing event is handled to add the Clear All item to the summary footer menu. Clicking this item cancels the summary calculations for all Tree List columns.

C#

using DevExpress.Utils.Menu;
using DevExpress.XtraTreeList;
using DevExpress.XtraTreeList.Columns;
//...
private void treeList1_PopupMenuShowing(object sender, DevExpress.XtraTreeList.PopupMenuShowingEventArgs e) {
    TreeList tL = sender as TreeList;
    TreeListHitInfo hitInfo = tL.CalcHitInfo(e.Point);
    if (hitInfo.HitInfoType == HitInfoType.SummaryFooter) {
        DXMenuItem menuItem = new DXMenuItem("Clear All", this.clearAllMenuItemClick);
        menuItem.Tag = hitInfo.Column;
        e.Menu.Items.Add(menuItem);
    }
}

private void clearAllMenuItemClick(object sender, EventArgs e) {
    TreeListColumn clickedColumn = (sender as DXMenuItem).Tag as TreeListColumn;
    if (clickedColumn == null) return;
    TreeList tl = clickedColumn.TreeList;
    foreach (TreeListColumn column in tl.Columns)
        column.SummaryFooter = SummaryItemType.None;
}

VB.NET

Imports DevExpress.Utils.Menu
Imports DevExpress.XtraTreeList
Imports DevExpress.XtraTreeList.Columns
'...
Private Sub TreeList1_PopupMenuShowing(sender As Object, e As DevExpress.XtraTreeList.PopupMenuShowingEventArgs) Handles TreeList1.PopupMenuShowing
    Dim tL As TreeList = sender
    Dim HitInfo As TreeListHitInfo = tL.CalcHitInfo(e.Point)
    If HitInfo.HitInfoType = HitInfoType.SummaryFooter Then
        Dim menuItem As New DXMenuItem("Clear All", AddressOf Me.clearAllMenuItemClick)
        menuItem.Tag = HitInfo.Column
        e.Menu.Items.Add(menuItem)
    End If
End Sub

Private Sub clearAllMenuItemClick(ByVal sender As Object, ByVal e As EventArgs)
    Dim clickedColumn As TreeListColumn = CType(CType(sender, DXMenuItem).Tag, TreeListColumn)
    If clickedColumn Is Nothing Then Return
    Dim treeList1 As TreeList = clickedColumn.TreeList
    For Each Column In treeList1.Columns
        Column.SummaryFooter = SummaryItemType.None
    Next
End Sub

How to: Display a Command that Deletes a Node

The example below shows how to display a custom context menu with a click on a node indicator. The menu contains the Delete Node command.

The TreeList.PopupMenuShowing event fires when the default menu is about to be shown. The TreeList.CalcHitInfo method in the event handler returns internal information about the clicked visual element. If a node indicator is clicked, the Delete Node command is added to the menu. The DXMenuItem.Click event handler removes the node.

C#

using DevExpress.Utils.Menu;
using DevExpress.XtraTreeList;
using DevExpress.XtraTreeList.Nodes;

private void treeList1_PopupMenuShowing(object sender, DevExpress.XtraTreeList.PopupMenuShowingEventArgs e) {
    // Check if a node's indicator cell is clicked.
    TreeListHitInfo hitInfo = (sender as TreeList).CalcHitInfo(e.Point);
    TreeListNode node = null;
    if (hitInfo.HitInfoType == HitInfoType.RowIndicator) {
        node = hitInfo.Node;
    }
    if (node == null) return;
    // Create the Delete Node command.
    DXMenuItem menuItem = new DXMenuItem("Delete Node", this.deleteNodeMenuItemClick);
    menuItem.Tag = node;
    e.Menu.Items.Add(menuItem);
}

private void deleteNodeMenuItemClick(object sender, EventArgs e) {
    DXMenuItem item = sender as DXMenuItem;
    if (item == null) return;
    TreeListNode node = item.Tag as TreeListNode;
    if (node == null) return;
    node.TreeList.DeleteNode(node);
}

VB.NET

Imports DevExpress.Utils.Menu
Imports DevExpress.XtraTreeList
Imports DevExpress.XtraTreeList.Nodes

Private Sub treeList1_PopupMenuShowing(ByVal sender As Object, ByVal e As DevExpress.XtraTreeList.PopupMenuShowingEventArgs)
    ' Check if a node's indicator cell is clicked.
    Dim hitInfo As TreeListHitInfo = (TryCast(sender, TreeList)).CalcHitInfo(e.Point)
    Dim node As TreeListNode = Nothing
    If hitInfo.HitInfoType = HitInfoType.RowIndicator Then
        node = hitInfo.Node
    End If
    If node Is Nothing Then
        Return
    End If
    ' Create the Delete Node command.
    Dim menuItem As New DXMenuItem("Delete Node", AddressOf Me.deleteNodeMenuItemClick)
    menuItem.Tag = node
    e.Menu.Items.Add(menuItem)
End Sub

Private Sub deleteNodeMenuItemClick(ByVal sender As Object, ByVal e As EventArgs)
    Dim item As DXMenuItem = TryCast(sender, DXMenuItem)
    If item Is Nothing Then
        Return
    End If
    Dim node As TreeListNode = TryCast(item.Tag, TreeListNode)
    If node Is Nothing Then
        Return
    End If
    node.TreeList.DeleteNode(node)
End Sub