DataGrid的C＃WPF / XAML预览鼠标事件

Question

I'm using a WPF DataGrid with c#/xaml in Visual Studio 2013.

With SelectionMode="Extended", I'm able to multi-select rows in the grid.

I have a requirement where clicks on one of the columns of the grid are to be ignored relative to row selection.

I setup a PreviewMouseLeftButtonDown event that gets called. Since it's a preview event, at the time of the event is processed, the selection in the grid hasn't changed yet. I'm able to determine the row and column of the click, so I can determine a click has been made in a column that I don't want

I want to be able to abort the click event at that point so that no change is made to the current selected items in the grid. Is that possible?

In the mouse down event I tried something like:

    private void GridCtrl_MouseDown(object sender, MouseButtonEventArgs e)
    {
          // ... Other code
          e.Handled = true;
    }

But, despite being marked as handled, it still continues and performs the row selection. I also have a 'SelectionChanged' event that I see that it later gets into.

Answer 1

I think you actually need to handle both tunneling events - one for PreviewLeftMOuseButtonDown and another for PreviewSelectionChanged.

My advice is create a flag, let's call it:

bool _cancelSelectionChange = false;

Then, in your Mouse handler:

private void GridCtrl_MouseDown(object sender, MouseButtonEventArgs e)
{
      _cancelSelectionChange = false;

      // ... Other code
      _cancelSelectionChange = true;
      e.Handled = true;
}

Finally, in your selection change handler for the tunneling event:

private void GridCtrl_PreviewSelectionChanged(object sender, SelectionChangedEventArgs e)
{
    e.Handled = _cancelSelectionChange;
}