Before touching the designer or editing any xaml, it's useful to do to a quick build and some work on the code behind in the window's .xaml.cs file.

1. Go to Build > Build Solution.
2. Now declare the public static RoutedCommands required for this project in the .xaml.cs file. Open MainWindow.xaml.cs and add code similar to the following within the body of your MainWindow class:
    

   C#	Copy Code
   public static RoutedCommand ExitCmd = new RoutedCommand(); public static RoutedCommand ZoomInCmd = new RoutedCommand(); public static RoutedCommand ZoomOutCmd = new RoutedCommand(); public static RoutedCommand Rotate90Cmd = new RoutedCommand(); public static RoutedCommand Rotate180Cmd = new RoutedCommand(); public static RoutedCommand Rotate270Cmd = new RoutedCommand();