BeginInvoke in TinyCLR

TinyCLR OS
1

In Gadgeteer I used Program.BeginInvoke()
Show an example how to use BeginInvoke correctly in TinyCLR

2

I tryed Dispatcher from GHIElectronics.TinyCLR.UI.Threading namespace

        private class Operation
        {
            public Operation(Delegate method, object[] args)
            {
                this.method = method;
                this.args = args;
            }
            public Delegate method;
            public object[] args;
        }

        private static DispatcherOperationCallback Operator = new DispatcherOperationCallback(DoOperation);
        private static object DoOperation(object op)
        {
            var operation = (Operation)op;
            try
            {
                operation.method.Method.Invoke(operation.method.Target, operation.args);
            }
            catch
            {
                Debug.WriteLine("Error invoking method \"" + operation.method.Method.DeclaringType + "\" (check arguments to Program.BeginInvoke are correct)");
            }

            return null;
        }

        public static void BeginInvoke(Delegate method, params object[] args)
        {
            if (method != null && Application.Current.Dispatcher != null)
            {
                if (args == null) args = new object[] { };
                Application.Current.Dispatcher.BeginInvoke(Operator, new Operation(method, args));
            }
        }

but sometimes I get an exception on the line
operation.method.Method.Invoke(operation.method.Target, operation.args);
and Visual Studio 2019 crashes.
Besides, I don’t understand why the Dispatcher is only available in the UI

3

What is the exception text? Do you have breakpoints set on the invoked method?

I get VS crashes during delegate invocation also, but only if I put a breakpoint on the start of the target delegate code. For some reason, breakpoints on the first instructions of a callee will cause VS to crash.

4

Yes. But my breakpoint not on the start of the target delegate code

5

If you remove the breakpoint, does vs still crash? I’m just wondering if we’re still seeing this scenario cause the debugger crash.

6

No.
If I put a breakpoint at the place where BeginInvoke was called

BeginInvoke(new SetDataDelegate(rc_DataReceived), new object[] { cmd_bufer, rcUart });

then continue debugging step by step, then I get VS crash and restart

7

Yup - that’s the same behavior I see. This seems to be a bug in the debugger framework (and also in VS itself, which is not supposed to crash, no matter what third-party extensions do). There’s no workaround that I know of other than to break elsewhere or use Debug.WriteLine to do your debugging. This will have to be fixed either in the firmware or the PC-side TinyCLR debugging support dll.

I’ll also try to get an internal issue reported on the VS crash. Even if TinyCLR extensions fail in some way, VS should not exit.