Xamarin forms: Showing DISABLE_XAML_GENERATED_BINDING_DEBUG_OUTPUT when loading a page

Question

Redirecting to App.g.i.cs when loading a page in xamarin UWP. Code control comes to the following if block.

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

If I mouse over the e showing {Windows.UI.Xaml.UnhandledExceptionEventArgs}

I am not understanding what is the problem? Is this related to some error in XAML? This issue is only on the windows app, Android and IOS apps parts are working fine.

XAML page code:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="Myproject.Pages.CodeValidationPage"
             BackgroundColor="#00aff0">

<ScrollView>
    <StackLayout
        VerticalOptions="FillAndExpand">
        <StackLayout 
        VerticalOptions="CenterAndExpand"
        Orientation="Vertical">

            <Image 
            Source="splash.png"
            HeightRequest="120"
            WidthRequest="120"
            IsVisible="True"
            HorizontalOptions="Center"
            VerticalOptions="CenterAndExpand"/>

            <Label
            Text=" Please check your email for the verification code and activate your account. "
            HorizontalOptions="CenterAndExpand"
                x:Name="italic_test"
            HorizontalTextAlignment="Center"
            Margin="3"
            Font="Italic,15"
            TextColor="White"/>

            <Frame
                HorizontalOptions="FillAndExpand"
                CornerRadius="10"
                Margin="20"
                Padding="0">

                <StackLayout 
                    BackgroundColor="White" 
                    Orientation="Vertical"
                    VerticalOptions="CenterAndExpand" >

                    <Entry 
                        x:Name="codeentry" 
                        Margin="10,10,10,0"
                        Keyboard="Numeric"
                        Placeholder="Enter Verification Code"/>

                    <Entry 
                        x:Name="passwordentry" 
                        Placeholder="Password" 
                        IsVisible="False"
                        Margin="10,10,10,0"
                        IsPassword="True"/>

                    <Entry 
                        x:Name="confirmpasswordentry" 
                        Margin="10,0,10,-10"
                        IsVisible="False"
                        Placeholder="Confirm Password"
                        IsPassword="True"/>

                    <Button
                        Text="Verify Code" 
                        HeightRequest="40"
                        WidthRequest="150"
                        x:Name="validationButton"
                        TextColor="White"
                        HorizontalOptions="CenterAndExpand"
                        Font="Bold,15"
                        Margin="5,15,5,10"
                        BorderRadius="20"
                        BackgroundColor="#00aff0" 
                        Clicked="SaveNewPassword"/>
                </StackLayout>
            </Frame>
        </StackLayout>

        <Label
            VerticalOptions="EndAndExpand"
            HorizontalOptions="CenterAndExpand"
            Margin="0,0,0,15"
                x:Name="backto_label"
                TextColor="White"
                Font="Bold,16"
                Text=" Back to Sign Up "/>
    </StackLayout>
</ScrollView>
</ContentPage>

Answer 1

With Xamarin.forms 3.x Microsoft moved to .net standard 2.0.

I was able to compile the code and run the app after converting your PCL to .net standard 2.0, updating all nuget packages to last version and changing xmlns:controls="clr-namespace:ImageCircle.Forms.Plugin.Abstractions;assembly=ImageCircle.Forms.Plugin.Abstractions" to xmlns:controls="clr-namespace:ImageCircle.Forms.Plugin.Abstractions;assembly=ImageCircle.Forms.Plugin" as stated in the documentation in your XAML files.

Clicking on ResetPassword shows a System.Collections.Generic.KeyNotFoundException at this line:

string initialLogin = Application.Current.Properties["initialLogin"].ToString();

So change it to

Application.Current.Properties.TryGetValue("initialLogin", out var initialLogin);

to handle the case that "initialLogin" was not added to the Application.Current.Properties collection. Next check the value for being != null before use it.

Also in Mainpage.xaml.cs you do the same mistake with username and password.

Also change PDB type from full to pdb-only to allow debugging. This is a known issue.

So reset works:

Answer 2

The real problem is with the disaplayalert.

I am using the following code for display alert:

await DisplayAlert("Alert", "A verification code has been sent to your email.", "OK");

If I changed the above lines like below, no issue will come.

Device.BeginInvokeOnMainThread(async () => 
{
    await DisplayAlert("Alert", "A verification code has been sent to your email.", "OK");
});