Xamarin Android debugging: No compatible code running

Question

Context

I am using VS 2017.3 to develop Xamarin.Forms application. I am trying to diagnose where and why an Exception occur on my code.

I can successfully deploy run and debug my application using the SDK Android Emulator (HAX x86).

However in case an Exception occur I can not see any information about the Exception, see attached picture, settings.

Question

Is this normal in Android debugging, or missing I something?

...and my build settings:

Answer 1

I wanted to expand on @Uraitz's answer because it helped me figure out the problem.

First, as he explains, you will want to add an event handler in your activity, as shown in the following code:

    protected override void OnCreate(Bundle savedInstanceState)
    {
        ...
        //subscribe to unhandled event  
        AppDomain.CurrentDomain.UnhandledException += CurrentDomainUnhandledException;
        ...
    }

    private void CurrentDomainUnhandledException(object sender, UnhandledExceptionEventArgs e)
    {
        System.Diagnostics.Debug.WriteLine(e.ToString());
    }

In my case I put a breakpoint inside CurrentDomainUnhandledException so I could inspect the exception.

However, even with that breakpoint in there, I ran my code and still got a confusing no-callstack error.

At this point I thought the solution wasn't working. In fact it is, but I had to click the Play (continue) button multiple times before my app would hit the breakpoint:

After clicking that button two times, I finally hit the breakpoint:

If you want to get the callstack in the debugger, you will have to dive in a few levels before it is available, but you can do so by looking at the event args parameter.

The moral of the story is - if you have added the event handler but you still aren't hitting the breakpoint (or seeing output) - keep clicking the Continue button!

Answer 2

Just continue, then look through the Output, it will show you the stack trace of the exception. It is a good idea to learn how to read through the log files to find information about exceptions.