Usage: WpfSingleInstance.Make(); or WpfSingleInstance.Make(SingleInstanceModes.ForEveryUser);
1. Add only a line of code (above) in the App.xaml.cs or in the main window.
2. Add a small static class in project (and a dummy enum SingleInstanceModes).
No additional inheritance in App class.
No App.xalm deleting.
No so redundant WCF and Remoting.
It works by the EventWaitHandle. Look in code, it's so simply.
I'm not worried about security of string-name for EventWaitHandle :( . It opt to you.
I needed a reliable, robust, simple, small solution.