App crashing on IOS Simulator

Question

App crashing on IOS Simulator

Sandeep Reddy Pinniti 1

Hi Team,

I have a basic login page, I'm running the app on iOS simualtor and developing the code in VS2022 on windows machine. The App crashes as soon as I focus the mouse on the Email text box. I have registered Unhandled Exception event, but the event is not firing. Will you please guide me in resolving this issue.

 AppDomain.CurrentDomain.UnhandledException += HandleUnhandledException;

private void HandleUnhandledException(object sender, UnhandledExceptionEventArgs e)
{
    // Log or handle the exception here
    Exception ex = (Exception)e.ExceptionObject;
    HandleError(ex, "App.HandleUnhandledException");
}

<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:viewModels="using:Biome.ViewModels"
             x:Class="Biome.LoginPage"
    x:DataType="viewModels:LoginViewModel">
    <ContentPage.BindingContext>
        <viewModels:LoginViewModel />
    </ContentPage.BindingContext>
    <VerticalStackLayout Padding="30,0" Spacing="25">
        <Image Source="biome.png" HeightRequest="185" Aspect="AspectFit" SemanticProperties.Description="biome" />
        <Grid HorizontalOptions="Center" VerticalOptions="Center">
            <Grid.RowDefinitions>
                <RowDefinition Height="45"></RowDefinition>
                <RowDefinition Height="5"></RowDefinition>
                <RowDefinition Height="45"></RowDefinition>
                <RowDefinition Height="5"></RowDefinition>
                <RowDefinition Height="45"></RowDefinition>
            </Grid.RowDefinitions>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="500"></ColumnDefinition>
            </Grid.ColumnDefinitions>
            <Entry Grid.Row="0" Placeholder="Email Address" Text="{Binding LoginModel.Email}" />
            <Entry Grid.Row="2" Placeholder="Password" IsPassword="True" Text="{Binding LoginModel.Password}" />
            <Button Grid.Row="4" Text="Login" Command="{Binding LoginCommand}" />
        </Grid>
    </VerticalStackLayout>

</ContentPage>

Thanks

Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 36,436 Reputation points Microsoft External Staff

2024-04-09T05:59:27.2566667+00:00

What the iOS version of the simulator? Do you have the same issue on other simulators?

In addition, I noticed that you set the binding for the Eamil entry.(<Entry Grid.Row="0" Placeholder="Email Address" Text="{Binding LoginModel.Email}" />)

Do you have the same issue when you remove the binding? And would you mind sharing more code snippets about the ViewModel so that I can test and reproduce the issue? Thanks for your understanding and collaboration.

Sandeep Reddy Pinniti 1

Hi,

It is working on Windows Simulator. Crashes on iPad Pro and iPhone Pro Max (iOS 17.4).

Even before posting, I have tried without the binding still had the same issue.

using System.Windows.Input; using Microsoft.Data.SqlClient;
using Newtonsoft.Json;

namespace Biome.ViewModels
{
    public class LoginViewModel : DataNotifier
    {
        private Login _loginModel;
        public ICommand LoginCommand { get; }

        public LoginViewModel()
        {
            _loginModel = new Login();
            LoginCommand = new Command(OnLoginClicked);
        }

        public Login LoginModel
        {
            get => _loginModel;
            set
            {
                _loginModel = value;
                OnPropertyChanged();
            }
        }

        private void OnLoginClicked()
        {
            if (IsValidEmail(LoginModel.Email))
            {
                if (!string.IsNullOrWhiteSpace(LoginModel.Password))
                {
                                         App.User = Database Call HERE 

                    if (App.User != null)
                    {
                        DisplayAlert("Success", "Login Successful for User: " + App.User.FullName, "OK");
                    }
                    else
                    {
                        DisplayAlert("Success", "User not found", "OK");
                    }
                }
                else
                {
                    DisplayAlert("Error", "Please enter your password.", "OK");
                }
            }
            else
            {
                DisplayAlert("Error", "Invalid email address.", "OK");
            }
        }

        private bool IsValidEmail(string email)
        {
            if (!string.IsNullOrWhiteSpace(email))
            {
                // Basic email validation using regular expression
                const string emailPattern = @"^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$";
                return System.Text.RegularExpressions.Regex.IsMatch(email, emailPattern);
            }
            return false;
        }

        private void DisplayAlert(string title, string message, string button)
        {
            Application.Current.MainPage.DisplayAlert(title, message, button);
        }
    }
}

Sandeep Reddy Pinniti 1

Hi,

I have run the App on windows simulator and didn't had any issue. I have tested it on iPad Pro/iPhone Pro Max (iOS 17.4) version. Before posting the query I have removed the Binding and still the App was crashing on focusing on the text box control. Attached View Model code for your reference.

using System.Windows.Input;
using Biome.DataAccessor;
using Biome.Infrastructure;
using Biome.Models;
using Microsoft.Data.SqlClient;
using Newtonsoft.Json;

namespace Biome.ViewModels
{
    public class LoginViewModel : DataNotifier
    {
        private Login _loginModel;
        public ICommand LoginCommand { get; }

        public LoginViewModel()
        {
            _loginModel = new Login();
            LoginCommand = new Command(OnLoginClicked);
        }

        public Login LoginModel
        {
            get => _loginModel;
            set
            {
                _loginModel = value;
                OnPropertyChanged();
            }
        }

        private void OnLoginClicked()
        {
            if (IsValidEmail(LoginModel.Email))
            {
                if (!string.IsNullOrWhiteSpace(LoginModel.Password))
                {
                    App.User = DATABASE CODE HERE
                    if (App.User != null)
                    {
                        DisplayAlert("Success", "Login Successful for User: " + App.User.FullName, "OK");
                    }
                    else
                    {
                        DisplayAlert("Success", "User not found", "OK");
                    }
                }
                else
                {
                    DisplayAlert("Error", "Please enter your password.", "OK");
                }
            }
            else
            {
                DisplayAlert("Error", "Invalid email address.", "OK");
            }
        }

        private bool IsValidEmail(string email)
        {
            if (!string.IsNullOrWhiteSpace(email))
            {
                // Basic email validation using regular expression
                const string emailPattern = @"^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$";
                return System.Text.RegularExpressions.Regex.IsMatch(email, emailPattern);
            }
            return false;
        }

        private void DisplayAlert(string title, string message, string button)
        {
            Application.Current.MainPage.DisplayAlert(title, message, button);
        }
    }
}

Thanks in advance.

1 answer

Your answer

Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 36,436 Reputation points Microsoft External Staff

2024-04-09T05:59:27.2566667+00:00

What the iOS version of the simulator? Do you have the same issue on other simulators?

In addition, I noticed that you set the binding for the Eamil entry.(<Entry Grid.Row="0" Placeholder="Email Address" Text="{Binding LoginModel.Email}" />)

Do you have the same issue when you remove the binding? And would you mind sharing more code snippets about the ViewModel so that I can test and reproduce the issue? Thanks for your understanding and collaboration.
Sandeep Reddy Pinniti 1 Reputation point

2024-04-09T20:06:54.4733333+00:00

Hi,

It is working on Windows Simulator. Crashes on iPad Pro and iPhone Pro Max (iOS 17.4).

Even before posting, I have tried without the binding still had the same issue.

using System.Windows.Input; using Microsoft.Data.SqlClient; using Newtonsoft.Json; namespace Biome.ViewModels { public class LoginViewModel : DataNotifier { private Login _loginModel; public ICommand LoginCommand { get; } public LoginViewModel() { _loginModel = new Login(); LoginCommand = new Command(OnLoginClicked); } public Login LoginModel { get => _loginModel; set { _loginModel = value; OnPropertyChanged(); } } private void OnLoginClicked() { if (IsValidEmail(LoginModel.Email)) { if (!string.IsNullOrWhiteSpace(LoginModel.Password)) { App.User = Database Call HERE if (App.User != null) { DisplayAlert("Success", "Login Successful for User: " + App.User.FullName, "OK"); } else { DisplayAlert("Success", "User not found", "OK"); } } else { DisplayAlert("Error", "Please enter your password.", "OK"); } } else { DisplayAlert("Error", "Invalid email address.", "OK"); } } private bool IsValidEmail(string email) { if (!string.IsNullOrWhiteSpace(email)) { // Basic email validation using regular expression const string emailPattern = @"^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$"; return System.Text.RegularExpressions.Regex.IsMatch(email, emailPattern); } return false; } private void DisplayAlert(string title, string message, string button) { Application.Current.MainPage.DisplayAlert(title, message, button); } } }
Sandeep Reddy Pinniti 1 Reputation point

2024-04-09T20:11:14.3233333+00:00

Hi,

I have run the App on windows simulator and didn't had any issue. I have tested it on iPad Pro/iPhone Pro Max (iOS 17.4) version. Before posting the query I have removed the Binding and still the App was crashing on focusing on the text box control. Attached View Model code for your reference.

using System.Windows.Input; using Biome.DataAccessor; using Biome.Infrastructure; using Biome.Models; using Microsoft.Data.SqlClient; using Newtonsoft.Json; namespace Biome.ViewModels { public class LoginViewModel : DataNotifier { private Login _loginModel; public ICommand LoginCommand { get; } public LoginViewModel() { _loginModel = new Login(); LoginCommand = new Command(OnLoginClicked); } public Login LoginModel { get => _loginModel; set { _loginModel = value; OnPropertyChanged(); } } private void OnLoginClicked() { if (IsValidEmail(LoginModel.Email)) { if (!string.IsNullOrWhiteSpace(LoginModel.Password)) { App.User = DATABASE CODE HERE if (App.User != null) { DisplayAlert("Success", "Login Successful for User: " + App.User.FullName, "OK"); } else { DisplayAlert("Success", "User not found", "OK"); } } else { DisplayAlert("Error", "Please enter your password.", "OK"); } } else { DisplayAlert("Error", "Invalid email address.", "OK"); } } private bool IsValidEmail(string email) { if (!string.IsNullOrWhiteSpace(email)) { // Basic email validation using regular expression const string emailPattern = @"^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$"; return System.Text.RegularExpressions.Regex.IsMatch(email, emailPattern); } return false; } private void DisplayAlert(string title, string message, string button) { Application.Current.MainPage.DisplayAlert(title, message, button); } } }

Thanks in advance.

Answer 1

Hello,

It is working on Windows Simulator. Crashes on iPad Pro and iPhone Pro Max (iOS 17.4).

The simulator is iOS17.2, right?

Xcode15.3 (with iOS17.4 SDK) support is in progress, please keep using Xcode 15.2 for the time being, and run the app on the devices lower than iOS17.2.

For more details, please refer to [META] Xcode 15.3 Support for .NET 8 and MAUI · Issue #21057 · dotnet/maui · GitHub

Best Regards,

Wenyan Zhang

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App crashing on IOS Simulator

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