如果已选择行，则在wpf datagrid中右键单击禁用行选择

Question

I am working on a datagrid which enable user to select multiple rows. but when user clicks on header of row the selection get lost.

How can I disable the row selection on right click if the row is already selected.

I tried to do it via Behavior

public class DataGridRowBehavior
{

    public static readonly DependencyProperty DisableSelectionOnRightClickProperty = DependencyProperty.RegisterAttached(
                "DisableSelectionOnRightClick",
                typeof(bool),
                typeof(DataGridRowBehavior),
                new UIPropertyMetadata(false, OnDisableSelectionOnRightClick));


    public static bool GetDisableSelectionOnRightClick(DependencyObject dgRow)
    {
        return (bool)dgRow.GetValue(DisableSelectionOnRightClickProperty);
    }

    public static void SetDisableSelectionOnRightClick(DependencyObject dgRow, bool value)
    {
        dgRow.SetValue(DisableSelectionOnRightClickProperty, value);
    }

    public static void SetListViewFocus(DependencyObject d, bool use)
    {
        d.SetValue(DisableSelectionOnRightClickProperty, use);
    }

    public static void OnDisableSelectionOnRightClick(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        DataGridRowHeader header = d as DataGridRowHeader;
        header.MouseRightButtonUp += header_MouseRightButtonUp;
    }

    static void header_MouseRightButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
    {
        var header = sender as DataGridRowHeader;

        if (header.IsRowSelected)
        {
            if (header.ContextMenu != null)
            {
                header.ContextMenu.IsOpen = true;
            }

            e.Handled = true;
        }
    }
}

But this one is not working correctly as other functionality of right click is also broken. eg Context menu. The context menu is not enabling its Application Commands.

Is there any other way to disable the selection or let the selection remain as it is if I click on any of the selected row?

Answer 1

You have two choices:

1. Either create custom DataGrid or DataGridRow and create SelectionChanging or Selection events. It's needed to prevent selection. This time, this controls have only SelectionChanged and Selected events. Next time, I think you could write code

2. If you do not want create custom controls you can create a Behavior . For example:

    public class SuppressButtonClickBehavior : Behavior<Button> { protected override void OnAttached() { base.OnAttached(); AssociatedObject.AddHandler(UIElement.PreviewMouseLeftButtonDownEvent, new RoutedEventHandler(OnPreviewMouseLeftButtonDown), true); } protected override void OnDetaching() { base.OnDetaching(); AssociatedObject.RemoveHandler(UIElement.PreviewMouseLeftButtonDownEvent, new RoutedEventHandler(OnPreviewMouseLeftButtonDown)); } private void OnPreviewMouseLeftButtonDown(Object sender, RoutedEventArgs e) { e.Handled = true; if (AssociatedObject.Command != null) { AssociatedObject.Command.Execute(AssociatedObject.CommandParameter); } } } 

If you want, you can make this code more flexible. But you must understand, that you can only set e.Handled to true to prevent selection.