GridMenuEventArgs.TargetElement Property

Gets the UI element for which the context menu is shown.

Namespace: DevExpress.Xpf.Grid

Assembly: DevExpress.Xpf.Grid.v18.2.Core.dll

Declaration

C#

public IInputElement TargetElement { get; }

VB.NET

Public ReadOnly Property TargetElement As IInputElement

Property Value

Type	Description
IInputElement	The element displayed within a View for which the context menu is shown.

Remarks

• Column Menu

  The TargetElement property returns the GridColumnHeader object that represents the column header for which the context menu is shown.

• Cell Menu

  The TargetElement property returns the DevExpress.Xpf.Grid.GridCellContentPresenter object that represents the data cell for which the context menu is shown.

• GroupPanel Menu

  The TargetElement property returns the ContentControl object that represents the Group Panel.

• Summary Menu

  The TargetElement property returns the DevExpress.Xpf.Grid.GridTotalSummary object.

Example

The following example demonstrates how to modify a column header in a grid’s Table View. In this sample, we illustrate how to add a button with an icon to a column header’s customization area.

For this, it is necessary to define a DataTemplate, which represents a button, and assign it to the DataViewBase.ColumnHeaderCustomizationAreaTemplate property. This template specifies a button and some of its properties. For example, it invokes the standard context menu on clicking this button (but disables invoking this menu when either the column header or the custom button within it are clicked).

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-add-a-custom-button-to-a-column-header-e1838.

Window1.xaml.cs

private void TableView_ShowGridMenu(object sender, GridMenuEventArgs e) {
    // Check whether this event was raised for a column's context menu.
    // If not - exit and leave the menu shown.
    if (e.MenuType != GridMenuType.Column) return;

    // Check whether this event was raised for a custom button.
    // If not - exit and hide the menu.
    if ((e.TargetElement as Control).Tag == null) {
        e.Handled = true;
        return;
    }
}

private void Button_Click(object sender, RoutedEventArgs e) {
    // Show the context menu when a custom button is clicked.
    view.GridMenu.ShowPopup(sender as Button);
}

private void Button_PreviewMouseRightButtonUp(object sender, MouseButtonEventArgs e) {
    // Don't show the context menu when a custom button is right-clicked.
    e.Handled = true;
}

Window1.xaml

<dxg:GridControl.View>
    <dxg:TableView Name="view" ShowGridMenu="TableView_ShowGridMenu">
        <dxg:TableView.ColumnHeaderCustomizationAreaTemplate>
            <DataTemplate>
                <Button Tag="custom" Click="Button_Click" PreviewMouseRightButtonUp="Button_PreviewMouseRightButtonUp" 
                        dxg:GridPopupMenu.GridMenuType="{x:Static dxg:GridMenuType.Column}">
                    <Button.Template>
                        <ControlTemplate TargetType="{x:Type Button}">
                            <Grid SnapsToDevicePixels="True" Background="Transparent">
                                <Path Name="path" Stretch="Fill" Fill="#FF0000FF" 
                                      Data="F1 M 1410.67,764.811L 1408.32,767.495C 1407.59,768.323 1406.36, 768.364 1405.59,767.586L 1405.41,767.414C 1404.64,766.636 1404.68, 765.407 1405.51,764.683L 1408.19,762.334C 1407.67,762.122 1407.1, 762 1406.5,762C 1404.01,762 1402,764.015 1402,766.5C 1402, 767.145 1402.14,767.755 1402.38,768.309L 1397.64,772.525C 1396.82, 773.257 1396.78,774.491 1397.56,775.269L 1397.73,775.44C 1398.51, 776.218 1399.74,776.182 1400.47,775.359L 1404.69,770.616C 1405.25, 770.86 1405.86,771.001 1406.5,771.001C 1408.98,771.001 1411, 768.985 1411,766.5C 1411,765.902 1410.88,765.333 1410.67,764.811 Z " 
                                      Width="14" Height="14" HorizontalAlignment="Center" VerticalAlignment="Center" />
                            </Grid>
                            <ControlTemplate.Triggers>
                                <Trigger Property="IsMouseOver" Value="True">
                                    <Setter Property="Fill" TargetName="path" Value="#FF00FF00" />
                                </Trigger>
                                <Trigger Property="IsPressed" Value="True">
                                    <Setter Property="Fill" TargetName="path" Value="#FFFF0000" />
                                </Trigger>
                            </ControlTemplate.Triggers>
                        </ControlTemplate>
                    </Button.Template>
                </Button>
            </DataTemplate>
        </dxg:TableView.ColumnHeaderCustomizationAreaTemplate>
    </dxg:TableView>
</dxg:GridControl.View>

Window1.xaml.vb

Private Sub TableView_ShowGridMenu(ByVal sender As Object, ByVal e As GridMenuEventArgs)
    ' Check whether this event was raised for a column's context menu.
    ' If not - exit and leave the menu shown.
    If e.MenuType <> GridMenuType.Column Then
        Return
    End If


    ' Check whether this event was raised for a custom button.
    ' If not - exit and hide the menu.
    If (TryCast(e.TargetElement, Control)).Tag Is Nothing Then
        e.Handled = True
        Return
    End If
End Sub

Private Sub Button_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
    ' Show the context menu when a custom button is clicked.
    view.GridMenu.ShowPopup(TryCast(sender, Button))
End Sub

Private Sub Button_PreviewMouseRightButtonUp(ByVal sender As Object, ByVal e As _
MouseButtonEventArgs)
    ' Don't show the context menu when a custom button is right-clicked.
    e.Handled = True
End Sub

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the TargetElement property.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

gridcontrol-how-to-rename-column-headers-at-runtime-e4187/CS/T686902/EditableColumnHeaderBehavior.cs#L37

if (e.MenuType == GridMenuType.Column) {
    GridColumnHeader columnHeader = e.TargetElement as GridColumnHeader;
    GridColumn column = columnHeader.DataContext as GridColumn;

VB.NET

gridcontrol-how-to-rename-column-headers-at-runtime-e4187/VB/T686902/EditableColumnHeaderBehavior.vb#L48

If e.MenuType = GridMenuType.Column Then
    Dim columnHeader As GridColumnHeader = TryCast(e.TargetElement, GridColumnHeader)
    Dim column As GridColumn = TryCast(columnHeader.DataContext, GridColumn)