What is XAML generated break on unhandled exception and app.g.i.cs file

Question

I am new to windows app development. I am trying to execute a solution on my local machine using x64 platform. But whenever I execute a Buttom_Click event I am getting this exception

#if DEBUG && !DISABLE_XAML_GENERATED_BREAK_ON_UNHANDLED_EXCEPTION
            UnhandledException += (sender, e) =>
            {
                if (global::System.Diagnostics.Debugger.IsAttached) global::System.Diagnostics.Debugger.Break();
            };
#endif

in App.g.i.cs file.

I am getting this exception when debugger hits the variable 'icon' below

 private async void Button_Click(object sender, RoutedEventArgs e)
        {
            RootObject myWeather =
                await OpenWeatherMapProxy.GetWeather(20.0,30.0);

            string icon = String.Format("ms-appx:///Assets/Weather/{0}.png", myWeather.weather[0].icon);
            ResultImage.Source = new BitmapImage(new Uri(icon, UriKind.Absolute));
            ResultTextBlock.Text = myWeather.name + " - " + ((int)myWeather.main.temp).ToString() + " - " + myWeather.weather[0].description;
        }

It would be helpful if anyone can explain how to get rid of this exception and what is App.g.i.cs file.

Answer 1

App.g.i.cs is an auto genearated file, and its breaking at that location because you haven't handled the exception properly in your code.

private async void Button_Click(object sender, RoutedEventArgs e)
{
    try{

    RootObject myWeather =
        await OpenWeatherMapProxy.GetWeather(20.0,30.0);

    string icon = String.Format("ms-appx:///Assets/Weather/{0}.png", myWeather.weather[0].icon);
    ResultImage.Source = new BitmapImage(new Uri(icon, UriKind.Absolute));
    ResultTextBlock.Text = myWeather.name + " - " + ((int)myWeather.main.temp).ToString() + " - " + myWeather.weather[0].description;

    }
    catch(Exception ex)
    {
       Debug.WriteLine(ex.Message);
       Debug.WriteLine(ex.StackTrace);
    }
}

Go to the Output window when the application is running and go through the exception detail, you might find the answer.

Mostlikely exception is causeded by myWeather or myWeather.weather[0] being null because OpenWeatherMapProxy.GetWeather failed to fetch the data.