Использование NavigationPage в Maui приводит к немедленному сбою приложения ⇐ IOS

[Anonymous]

Я разрабатываю приложение для iOS Maui, и я получил полностью функциональное приложение, которое работает без проблем. Проблема, которая у меня есть, заключается в том, что в Android нет кнопки «обратно», которая позволяет пользователю вернуться на предыдущую страницу, и не существует навигации , как то, что генерируется по умолчанию в Xamarin.
Как я понимаю, способность отключения отключена, если не использует навигационную мону Navigationbar или navigationpage Итак, у пользователя есть эта стрелка или кнопку обратной стрелки, чтобы вернуться на предыдущий экран. Я использовал пример здесь, чтобы добавить код, который мне нужен для появления панели. Но как только я добавляю этот код в свой App.xaml.cs Files < /p>
MainPage = new NavigationPage(new Logon());
< /code>
Приложение немедленно сбои, когда я запускаю его на своем тестовом устройстве. Приложение разбивается в строке 'uiapplication.main (args, null, typeof (appdelegate));
' в файле кода Program.cs в папке iOS с системой ошибок. NullReanceExexcept экземпляр объекта. . Этот код: < /p>
public class Program
{
// This is the main entry point of the application.
static void Main(string[] args)
{
// if you want to use a different Application Delegate class from "AppDelegate"
// you can specify it here.
UIApplication.Main(args, null, typeof(AppDelegate));
}
}
< /code>
Я сообщил о проблеме Microsoft здесь для тех, кто хочет посмотреть все мои исследования до сих пор. Было несколько проблем, с которыми я сталкивался, когда пробовал разные вещи, все это было прояснилось после обновления моего Mac и тестирования iPhone до последней ОС. < /P>
****** **** РЕДАКТИРОВАТЬ *********************
Это вход в систему код: < Br />public partial class Logon : ContentPage
{
public Logon()
{
InitializeComponent();
}
User MyUser = new User();
CompanyInformation MyCompany = new CompanyInformation();
bool error = false;
private async void OnCounterClicked(object sender, EventArgs e)
{
string username = TheUsername.Text;
string password = ThePassword.Text;
if (username != null)
{
if (password != null)
{
activityIndicator.IsVisible = true;
#if ANDROID
await Task.Run(() => SignOn());
#elif IOS
iOSSignon();
#endif
}
else
{
await DisplayAlert("ERROR", "Enter your password.", "OK");
}
}
else
{
await DisplayAlert("ERROR", "Enter your username.", "OK");
}

}
public void iOSSignon()
{
string result = "";

MyUser.Username = TheUsername.Text.Trim();
MyUser.Password = ThePassword.Text.Trim();
try
{

bool isOnline = Utils.IsConnectedToTheInternet();

if (isOnline)
{
MyServiceSoapClient myService = new MyServiceSoapClient(MyServiceSoapClient.EndpointConfiguration.MyServiceSoap);
try
{
result = myService.Logon(MyUser.Username, MyUser.Password);
}
catch (Exception ex)
{
Utils.LogError("App:MyApp/Logon.xaml.cs/SignOn - An error occured in SignOn function, the error is: " + ex.Message + System.Environment.NewLine + Utils.GetExceptionInfo(ex));
DisplayAlert("ERROR", "There was an error in the logon process. The error was reported to technical support, please try again later of contact technical support at Support@MyCompany.com.", "OK");
}
}
else
{
DisplayAlert("Information", "There is no internet connection or cell phone connection. Connect to a wifi network or a cellular network.", "OK");
}
}
catch (Exception ex)
{
Utils.LogError("App:MyApp/Logon.xaml.cs - An error occured in the SignOn function, the error is: " + ex.Message + System.Environment.NewLine + Utils.GetExceptionInfo(ex));
DisplayAlert("ERROR", "An error occured in the logon process. The error was reported to technical support, please try again later or contact technical support at Support@MyCompany.com.", "OK");
}

if (result == "CONNECTED")
{
Menu MyMenu = new Menu();
MyMenu.MyUser = MyUser;
Navigation.PushModalAsync(MyMenu);
}
else if (result == "DISABLED")
{
DisplayAlert("Information", "Your account has been disabled, contact your supervisor for more information.", "OK");
}
else
{
try
{
error = true;
DisplayAlert("Information", "Invalid username or password.", "OK");
}
catch (Exception ex)
{
Utils.LogError("App:MyApp/Logon.xaml.cs/SignOn() - An error occured in the Logon.xaml.cs SignOn function result = connected, the error is: " + ex.Message + System.Environment.NewLine + Utils.GetExceptionInfo(ex));
DisplayAlert("ERROR", "An error occurred during the logon process. The error has been reported to technical support, please try again or contact technical support at Support@MyCompany.com", "OK");
}
}
;
try
{
if (error)
{
Utils.LogError("App:MyApp/Logon.xaml.cs/SignOn() (2) - An error occured in the Logon.xaml.cs SignOn function result = connected, the error is: ");
}
}
catch (Exception ex)
{
Utils.LogError("App:MyApp/Logon.xaml.cs/SignOn() (2) - An error occured in Logon.xaml.cs Signin function (second block), the error is: " + ex.Message + System.Environment.NewLine + Utils.GetExceptionInfo(ex));
DisplayAlert("ERROR", "An error occurred during the logon process (2). The error has been reported to technical support, please try again or contact technical support at Support@MyCompany.com", "OK");
}
}
private async Task SignOn()
{
string result = "";

MyUser.Username = TheUsername.Text.Trim();
MyUser.Password = ThePassword.Text.Trim();
try
{

bool isOnline = Utils.IsConnectedToTheInternet();

if (isOnline)
{
MyServiceSoapClient myService = new MyServiceSoapClient(MyServiceSoapClient.EndpointConfiguration.MyServiceSoap);
try
{
result = myService.Logon(MyUser.Username, MyUser.Password);
}
catch (Exception ex)
{
Utils.LogError("App:MyApp/Logon.xaml.cs/SignOn - An error occured in SignOn function, the error is: " + ex.Message + System.Environment.NewLine + Utils.GetExceptionInfo(ex));
await DisplayAlert("ERROR", "There was an error in the logon process. The error was reported to technical support, please try again later of contact technical support at Support@MyCompany.com.", "OK");
}
}
else
{
await DisplayAlert("Information", "There is no internet connection or cell phone connection. Connect to a wifi network or cellular network.", "OK");
}
;
}
catch (Exception ex)
{
Utils.LogError("App:MyApp/Logon.xaml.cs - An error occured in the SignOn function, the error is: " + ex.Message + System.Environment.NewLine + Utils.GetExceptionInfo(ex));
await DisplayAlert("ERROR", "An error occured in the logon process. The error was reported to technical support, please try again later or contact technical support at Support@MyCompany.com.", "OK");
}
;

if (result == "CONNECTED")
{
Menu MyMenu = new Menu();
MyMenu.MyUser = MyUser;
await Navigation.PushModalAsync(MyMenu);
}
else if (result == "DISABLED")
{
await DisplayAlert("Information", "Your account has been disabled, contact your subervisor for more information.", "OK");
}
else
{
try
{
error = true;
await DisplayAlert("Information", "Invalid username or password.", "OK");
}
catch (Exception ex)
{
Utils.LogError("App:MyApp/Logon.xaml.cs/SignOn() - An error occured in the Logon.xaml.cs SignOn function result = connected, the error is: " + ex.Message + System.Environment.NewLine + Utils.GetExceptionInfo(ex));
await DisplayAlert("ERROR", "An error occurred during the logon process. The error has been reported to technical support, please try again or contact technical support at Support@MyCompany.com", "OK");
}
}
;
try
{
if (error)
{
Utils.LogError("App:MyApp/Logon.xaml.cs/SignOn() (2) - An error occured in the Logon.xaml.cs SignOn function result = connected, the error is: ");
}
}
catch (Exception ex)
{
Utils.LogError("App:MyApp/Logone.xaml.cs/SignOn() (2) - An error occured in Logon.xaml.cs Signin function (second block), the error is: " + ex.Message + System.Environment.NewLine + Utils.GetExceptionInfo(ex));
await DisplayAlert("ERROR", "An error occurred during the logon process (2). The error has been reported to technical support, please try again or contact technical support at Support@MyCompany.com", "OK");
}
}
}


Подробнее здесь: https://stackoverflow.com/questions/794 ... mmediately