识别从其继承属性的基础 class

Question

In order to clean up my code by using pattern matching, i need to find the common base class from which a certain common property is inherited from.

In the following exemple, the sender is a wpf DataTemplate consisting of a Grid with several UIElement on it. I want to initiate a drag event with the source of the data template, a Vehicle that can be accessed from any object's DataContext property.

I need to find the common base class from which my UIElements inherit the DataContext property in order to write clean code:

private void Grid_MouseDown(object sender, MouseButtonEventArgs e)
{
   if (e.LeftButton == MouseButtonState.Pressed)
   {
      if (e.Source is CommonBaseClassFromWhichDataContextPropertyIsInherited obj)
      {
         var vehicle = obj.DataContext;
         DataObject data = new DataObject();
         data.SetData(typeof(Vehicle), vehicle);
         DragDrop.DoDragDrop(this, data, DragDropEffects.Move);
      }
   }
}

@thatguy answered for my exemple: FrameWorkElement is the class I'm looking for.

But my question is more about the method to determine the base class : Do you browse metadata? Is there an intellisense function?

Answer 1

The FrameworkElement type defines the DataContext property, so you can match it.

if (e.Source is FrameworkElement frameworkElement)
{
   var vehicle = frameworkElement.DataContext;
   // ...
}

Methods to determine the base class:

• Use IntelliSense to browse the metadata, eg click on DataContext in XAML or C# code and hit F12 or right-click and select Go to definition .
• Google wpf [Name of the property] property , look for the docs.microsoft.com/... link.
• Remember a long forgotten training where it was mentioned or one of the countless blogs or other sites where you searched for something completely different and learned it by accident.
• Ask a question on StackOverflow , get an answer (warning, recursive).
• Meet your future self who knows it already through time travel, but be careful to not break the space-time continuum, been there, done that, hard to fix, even harder to explain.
• Join the dark side and use unlimited power, alternatively become a Jedi and meditate.