Question

i want to add an event to my Event handler. The Problem is my EventHandler is in my ViewModel and my Event is in View. How can I access my ViewModel from View to hang on this event?

thanks for your help

Answer 1

Since the view model is set as DataContext of the view you can subscribe to the DataContextChanged of the view and in the handler cast the DataContext to the view model’s type and attach the desired event handler. Something like this:

public class MyView : UserControl
{
   public MyView()
   {
       InitializeComponent();

       DataContextChanged += OnDataContextChanged;
   }

   private void OnDataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
   {
      MyViewModel viewModel = DataContext as MyViewModel;

      if (viewModel != null) 
      {
          viewModel.MyEvent += OnMyEvent;
      }
   }
}