invalidOperationException

[jianping jia]

MasterWindowController.cs

throw exception code

Window.DidResize += (sender, e) => {
				// Do something as the window is being live resized
			};

			Window.DidEndLiveResize += (sender, e) => {
				// Do something after the user's finished resizing
				// the window
			};

exception

System.InvalidOperationException: Event registration is overwriting existing delegate. Either just use events or your own delegate: MacWindows.MasterWindowController AppKit.NSWindow+_NSWindowDelegate
  at AppKit.NSApplication.EnsureEventAndDelegateAreNotMismatched (System.Object del, System.Type expectedType) [0x0001e] in /Library/Frameworks/Xamarin.Mac.framework/Versions/6.6.0.12/src/Xamarin.Mac/AppKit/NSApplication.cs:112
  at AppKit.NSWindow.EnsureNSWindowDelegate () [0x0000e] in /Library/Frameworks/Xamarin.Mac.framework/Versions/6.6.0.12/src/Xamarin.Mac/NSWindow.g.cs:11408
  at AppKit.NSWindow.add_DidResize (System.EventHandler value) [0x00001] in /Library/Frameworks/Xamarin.Mac.framework/Versions/6.6.0.12/src/Xamarin.Mac/NSWindow.g.cs:12068
  at MacWindows.MasterWindowController.WindowDidLoad () [0x00008] in /Users/anglehuang/Downloads/Xamarin_Mac___MacWindows/MacWindows/MasterWindowController.cs:21
  at at (wrapper managed-to-native) AppKit.NSApplication.NSApplicationMain(int,string[])
  at AppKit.NSApplication.Main (System.String[] args) [0x00040] in /Library/Frameworks/Xamarin.Mac.framework/Versions/6.6.0.12/src/Xamarin.Mac/AppKit/NSApplication.cs:100
  at MacWindows.MainClass.Main (System.String[] args) [0x00007] in /Users/anglehuang/Downloads/Xamarin_Mac___MacWindows/MacWindows/Main.cs:10

[Whitney Schmidt]

@xjfjian Thank you for your feedback!

I was able to reproduce this issue with the default sample code for MacWindows.

[Whitney Schmidt]

@xjfjian I've put out a PR with a fix for this issue. Please feel free to copy/paste to fix the sample locally on your machine.

There are also a couple other workarounds:

• (Preferred) Stop using C# events and create your own delegate and assign that
• Null out the existing delegate with Window.WeakDelegate = null;
• Disable the safely check with NSApplication.CheckForEventAndDelegateMismatches = false;