c# - 挂起线程花费的时间超过了允许的时间

Question

我使用 MvvmCross 并有一个简单的 AppStart 类:

public class AppStart: MvxNavigatingObject, IMvxAppStart
{
    /// <summary>
    /// The login service.
    /// </summary>
    private readonly IUserDataService _userService;

    public AppStart(IUserDataService userService)
    {
        _userService = userService;
    }

    public async void Start(object hint = null)
    {
        // If your application uses a secure API this first call attempts to log the user into the application
        // using any credentials stored from a previous session.  If there are
        // none stored we should present the login screen, else go straight into the app
        if (await _userService.Login())
        {
            ShowViewModel<MainViewModel>();
        }
        else
        {
            ShowViewModel<LoginViewModel>();
        }
    }
}

当我尝试调试应用程序时，它在显示闪屏后立即崩溃并出现以下错误:

suspend_thread suspend took 201 ms, which is more than the allowed 200 ms

如果我注释掉 userService.Login() 行就可以了

此错误是在我升级到 Xamarin 4.2.2.11 后出现的，但我不知道它是否与此更新有关。我使用 Xamarin.Android 7.0.2.42

我正在寻找一种永不挂起线程的方法，所以基本上我期望异步 Start 方法应该在 MvvmCross 中工作，但似乎并非如此，或者我可能没有做好事

这是 logcat 日志:

    Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Support.V7.Fragging[0x7f73a477de00] -> mscorlib[0x7f73a477c700]: 26
Tablet_API_21   Error   6091        suspend_thread suspend took 201 ms, which is more than the allowed 200 ms
Tablet_API_21   Debug   6091    gralloc_ranchu  Emulator without host-side GPU emulation detected.
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Platform[0x7f73abc78580] -> System.Reflection.Extensions[0x7f7394645680]: 3
Tablet_API_21   Warning 2180    IInputConnectionWrapper showStatusIcon on inactive InputConnection
Tablet_API_21   Debug   6091    OpenGLRenderer  Enabling debug mode 0
Tablet_API_21   Info    6091    OpenGLRenderer  Initialized EGL, version 1.4
Tablet_API_21   Debug   6091    OpenGLRenderer  Render dirty regions requested: true
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref VoxStarterXamarin.Droid[0x7f73a477d100] -> Xamarin.Android.Support.v4[0x7f7394618a00]: 4
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref VoxStarterXamarin.Droid[0x7f73a477d100] -> Square.AndroidTimesSquare[0x7f7394618680]: 2
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Support.V7.AppCompat[0x7f73a477d380] -> Mono.Android[0x7f7394646a80]: 16
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Support.V7.AppCompat[0x7f73a477d380] -> mscorlib[0x7f73a477c700]: 28
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Shared[0x7f73a477db00] -> Mono.Android[0x7f7394646a80]: 15
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Shared[0x7f73a477db00] -> mscorlib[0x7f73a477c700]: 27
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Support.V7.Fragging[0x7f73a477de00] -> Mono.Android[0x7f7394646a80]: 14
Tablet_API_21   Info    1490    ActivityManager Displayed VoxStarterXamarin.Droid.VoxStarterXamarin.Droid/md5d102fb223d7168b41e10cb7cf854dfb3.SplashScreen: +9s623ms
Tablet_API_21   Error   1490    InputDispatcher channel '302f064b VoxStarterXamarin.Droid.VoxStarterXamarin.Droid/md5d102fb223d7168b41e10cb7cf854dfb3.SplashScreen (server)' ~ Channel is unrecoverably broken and will be disposed!
Tablet_API_21   Warning 1490    InputDispatcher channel '302f064b VoxStarterXamarin.Droid.VoxStarterXamarin.Droid/md5d102fb223d7168b41e10cb7cf854dfb3.SplashScreen (server)' ~ Consumer closed input channel or an error occurred.  events=0x9
Tablet_API_21   Warning 1490    ActivityManager Force removing ActivityRecord{1b02a099 u0 VoxStarterXamarin.Droid.VoxStarterXamarin.Droid/md5d102fb223d7168b41e10cb7cf854dfb3.SplashScreen t19}: app died, no saved state
Tablet_API_21   Info    1490    ActivityManager Process VoxStarterXamarin.Droid.VoxStarterXamarin.Droid (pid 6091) has died
Tablet_API_21   Info    1141    Zygote  Process 6091 exited due to signal (6)
Tablet_API_21   Error   1490    InputDispatcher channel '302f064b VoxStarterXamarin.Droid.VoxStarterXamarin.Droid/md5d102fb223d7168b41e10cb7cf854dfb3.SplashScreen (server)' ~ Channel is unrecoverably broken and will be disposed!
Tablet_API_21   Warning 1490    InputDispatcher channel '302f064b VoxStarterXamarin.Droid.VoxStarterXamarin.Droid/md5d102fb223d7168b41e10cb7cf854dfb3.SplashScreen (server)' ~ Consumer closed input channel or an error occurred.  events=0x9
Tablet_API_21   Info    1490    ActivityManager Displayed VoxStarterXamarin.Droid.VoxStarterXamarin.Droid/md5d102fb223d7168b41e10cb7cf854dfb3.SplashScreen: +9s623ms
Tablet_API_21   Error   6091        suspend_thread suspend took 201 ms, which is more than the allowed 200 ms
Tablet_API_21   Debug   6091    gralloc_ranchu  Emulator without host-side GPU emulation detected.
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Platform[0x7f73abc78580] -> System.Reflection.Extensions[0x7f7394645680]: 3
Tablet_API_21   Warning 2180    IInputConnectionWrapper showStatusIcon on inactive InputConnection
Tablet_API_21   Debug   6091    OpenGLRenderer  Enabling debug mode 0
Tablet_API_21   Info    6091    OpenGLRenderer  Initialized EGL, version 1.4
Tablet_API_21   Debug   6091    OpenGLRenderer  Render dirty regions requested: true
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref VoxStarterXamarin.Droid[0x7f73a477d100] -> Xamarin.Android.Support.v4[0x7f7394618a00]: 4
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref VoxStarterXamarin.Droid[0x7f73a477d100] -> Square.AndroidTimesSquare[0x7f7394618680]: 2
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Support.V7.AppCompat[0x7f73a477d380] -> Mono.Android[0x7f7394646a80]: 16
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Support.V7.AppCompat[0x7f73a477d380] -> mscorlib[0x7f73a477c700]: 28
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Shared[0x7f73a477db00] -> Mono.Android[0x7f7394646a80]: 15
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Shared[0x7f73a477db00] -> mscorlib[0x7f73a477c700]: 27
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Support.V7.Fragging[0x7f73a477de00] -> Mono.Android[0x7f7394646a80]: 14
Tablet_API_21   Debug   6091    Mono    Assembly Ref addref MvvmCross.Droid.Support.V7.Fragging[0x7f73a477de00] -> mscorlib[0x7f73a477c700]: 26

一个重要的注意事项是，即使我在 Debug模式下构建和部署，它也能正常工作，只有当我进入 Debug模式(Visual Studio 2015 中的 F5)时才会出现错误

Answer 1

对于您的应用程序到达其第一个屏幕所需的时间，每个操作系统都有时间限制。 iOS 对此特别严格。 MvvmCross 也在他们的启动过程中强制执行这一点。

基本上，您的 await _userService.Login() 花费的时间太长。

您应该考虑将其移至其他位置。我的建议是为 Splash Screen 创建一个不同的页面，立即显示，然后在 Splsh 页面打开后开始您的登录过程。登录检查完成后，将新页面推送到 Splash 上，并从历史记录中删除 Splash 页面。