wpf eventsetter handler binding in style

Question

I have a style, and I want to bind a command to the EventSetter\'s Handler with RelativeSource. The command is in the viewModel.

Answer 1

Right now you are binding the MouseLeftButtonDown Event to TextBlock.TextBlockMouseLeftButtonDownCommand. TextBlockMouseLeftButtonDownCommand is not a valid property for a TextBlock, nor does it sound like it's an Event Handler.

I use the AttachedCommandBehavior all the time in styles for hooking up a Command to an Event. The syntax usually looks like this (note the DataContextin the Command Binding):

The alternative is to hook the EventSetter up to an event in the code-behind, and process the command from there:

Event handler in code behind...

void TextBlockMouseLeftButtonDown(object sender, MouseEventArgs e)
{
    var tb = sender as TextBlock;
    if (tb != null)
    {
        MyViewModel vm = tb.DataContext as MyViewModel;

        if (vm != null && TextBlockMouseLeftButtonDownCommand != null
            && TextBlockMouseLeftButtonDownCommand.CanExecute(null))
        {
            vm.TextBlockMouseLeftButtonDownCommand.Execute(null)
        }
    }
}