Question

我正在使用here中的以下代码。

Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
            @Override
            public void uncaughtException(Thread paramThread, Throwable paramThrowable) {
                // Catch your exception
                // Without System.exit() this will not work.
                System.exit(2);
            }
        });

我想在C＃中使用它。但是，我无法在C＃中找到这种方法的等效方法。我想使用Toast.makeText()向用户显示错误。

Answer 1

尝试这样的事情 -

AppDomain.CurrentDomain.UnhandledException += <Put your own delegate or handler>;
TaskScheduler.UnobservedTaskException += <Put your own delegate or handler here>;

理想情况下，您希望在执行程序期间执行不超过一次的某个位置执行此操作。如果是Xamarin.Android应用程序，您可以将其放在自定义应用程序类onCreate方法中。

如果您需要代码示例，请检查此链接（我自己没有运行代码，因此无法保证其正确性。仅将其用作参考） - Sample

// In MainActivity
protected override void OnCreate(Bundle bundle)
{
    base.OnCreate(bundle);  

    AppDomain.CurrentDomain.UnhandledException += CurrentDomainOnUnhandledException;
    TaskScheduler.UnobservedTaskException += TaskSchedulerOnUnobservedTaskException;  

    Xamarin.Forms.Forms.Init(this, bundle);  
    DisplayCrashReport();  

    var app = new App();  
    LoadApplication(app);
}  

‪#‎region‬ Error handling
private static void TaskSchedulerOnUnobservedTaskException(object sender, UnobservedTaskExceptionEventArgs unobservedTaskExceptionEventArgs)
{
    var newExc = new Exception("TaskSchedulerOnUnobservedTaskException", unobservedTaskExceptionEventArgs.Exception);
    LogUnhandledException(newExc);
}  

private static void CurrentDomainOnUnhandledException(object sender, UnhandledExceptionEventArgs unhandledExceptionEventArgs)
{
    var newExc = new Exception("CurrentDomainOnUnhandledException", unhandledExceptionEventArgs.ExceptionObject as Exception);
    LogUnhandledException(newExc);
}  

internal static void LogUnhandledException(Exception exception)
{
    try
    {
        const string errorFileName = "Fatal.log";
        var libraryPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal); // iOS: Environment.SpecialFolder.Resources
        var errorFilePath = Path.Combine(libraryPath, errorFileName);  
        var errorMessage = String.Format("Time: {0}\r\nError: Unhandled Exception\r\n{1}",
        DateTime.Now, exception.ToString());
        File.WriteAllText(errorFilePath, errorMessage);  

        // Log to Android Device Logging.
        Android.Util.Log.Error("Crash Report", errorMessage);
    }
    catch
    {
        // just suppress any error logging exceptions
    }
}  

/// <summary>
// If there is an unhandled exception, the exception information is diplayed 
// on screen the next time the app is started (only in debug configuration)
/// </summary>
[Conditional("DEBUG")]
private void DisplayCrashReport()
{
    const string errorFilename = "Fatal.log";
    var libraryPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
    var errorFilePath = Path.Combine(libraryPath, errorFilename);

    if (!File.Exists(errorFilePath))
    {
        return; 
    }

    var errorText = File.ReadAllText(errorFilePath);
    new AlertDialog.Builder(this)
        .SetPositiveButton("Clear", (sender, args) =>
        {
            File.Delete(errorFilePath);
        })
        .SetNegativeButton("Close", (sender, args) =>
        {
            // User pressed Close.
        })
        .SetMessage(errorText)
        .SetTitle("Crash Report")
        .Show();
} 

‪#‎endregion‬  

//iOS: Different than Android. Must be in FinishedLaunching, not in Main.
// In AppDelegate
public override bool FinishedLaunching(UIApplication uiApplication, NSDictionary options)
{
    AppDomain.CurrentDomain.UnhandledException += CurrentDomainOnUnhandledException;
    TaskScheduler.UnobservedTaskException += TaskSchedulerOnUnobservedTaskException;  
    ...
}  

/// <summary>
// If there is an unhandled exception, the exception information is diplayed 
// on screen the next time the app is started (only in debug configuration)
/// </summary>
[Conditional("DEBUG")]
private static void DisplayCrashReport()
{
    const string errorFilename = "Fatal.log";
    var libraryPath = Environment.GetFolderPath(Environment.SpecialFolder.Resources);
    var errorFilePath = Path.Combine(libraryPath, errorFilename);

    if (!File.Exists(errorFilePath))
    {
        return;
    }

    var errorText = File.ReadAllText(errorFilePath);
    var alertView = new UIAlertView("Crash Report", errorText, null, "Close", "Clear") { UserInteractionEnabled = true };
    alertView.Clicked += (sender, args) =>
    {
        if (args.ButtonIndex != 0)
        {
            File.Delete(errorFilePath);
        }
    };
    alertView.Show();
}

Answer 2

以下帖子已完成

仅在android平台上，您需要向其添加“ AndroidEnvironment.UnhandledExceptionRaiser”事件

AndroidEnvironment.UnhandledExceptionRaiser += OnAndroidEnvironmentUnhandledExceptionRaiser;
private void OnAndroidEnvironmentUnhandledExceptionRaiser(object sender, RaiseThrowableEventArgs unhandledExceptionEventArgs)
    {
        var newExc = new Exception("OnAndroidEnvironmentUnhandledExceptionRaiser", unhandledExceptionEventArgs.Exception);
        LogUnhandledException(newExc);
    }

捕获android中的所有异常（xamarin）

2 个答案: