Multiple Command Binding

Question

Is it possible to bind the multiple commands to the button.

I have a user control, which i am calling in my main application (parent application).

I want to handle a click command on both the controls (the user control as well as on the main window). However i am only able to get one.

Is there any way in which i can get this.

Any help is really appreciated.

Code Snippet:

public class MainWindowFooterCommands
{
    public static readonly RoutedUICommand FooterClickLocalCommand = new RoutedUICommand("Local Button Command", "FooterClickLocalCommand", typeof(MainWindowFooterCommands));
}

private void MainWindowFooterBindCommands()
{
    CommandBinding cmdBindingBXClick = new CommandBinding(MainWindowFooterCommands.FooterClickLocalCommand);
        cmdBindingBXClick.Executed += ClickCommandHandler;
        CommandBindings.Add(cmdBindingBXClick);
}


void ClickCommandHandler(object sender, ExecutedRoutedEventArgs e)
{
    //Do Something
}


//Parent Control holding an instance of the footer control.
class MainWindow {

    public MainWindow() 
    {
     CommandBinding cmdBindingBXClick1 = new CommandBinding(MainWindowFooterCommands.BXClickMainWindowCommand);
     cmdBindingBXClick1.Executed += LoadParent; 
     CommandBindings.Add(cmdBindingBXClick1);
    }

        public void LoadParent(object sender, ExecutedRoutedEventArgs e)
        {   
     LoadParentWindow();
        }
}

Regards, Tushar

Answer 1

AFAIK WPF doesnt offer anything out of the box to support multiple commandbindings at various levels, but you could try the following:

void ClickCommandHandler(object sender, ExecutedRoutedEventArgs e)
{
    IInputElement parent = (IInputElement) LogicalTreeHelper.GetParent((DependencyObject)sender);
    MainWindowFooterCommands.BXClickMainWindowCommand.Execute(e.Parameter, parent);
}

You might have to test whether your parent really is an IInputElement, though.

Answer 2

You might be trying to aggregate multiple commands, which is a natural thing to want to do.

If you are using Prism, there is a class builtin for this called the CompositeCommand (scroll down a bit): http://msdn.microsoft.com/en-us/library/cc707894.aspx

Otherwise, Josh Smith has a very good article on his implementation called a "Command Group": http://www.codeproject.com/KB/WPF/commandgroup.aspx

There are some very nice scenarios you can rollup like this (for instance, "Save All"). A good tool for your bag of tricks.