c# - 引发 Task.ThrowIfExceptional 的异常是什么？

Question

我有一个使用 C# 和 .NET Framework 4.0 运行任务开发的 Windows 窗体应用程序。

很抱歉问这个问题，但我不知道异常发生在哪里。这是堆栈跟踪:

One or more errors occurred.
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at MyCompany.Dispositivos.Plugins.TICAnKorr.DeviceTICAnKorr.StopLive()
   at MyCompany.Dispositivos.Plugins.TICAnKorr.VisorTICAnKorrMini.StopRemote()
   at MyCompany.Dispositivos.InterfazDispositivos.ICBaseVisor.DesasociarDispositivo()
   at MyCompany.Dispositivos.InterfazDispositivos.ControlMosaico.DesasociarTodosLosPaneles()
   at MyCompany.Dispositivos.InterfazDispositivos.ControlMosaico.CrearControlSeleccionado(DeviceBase device)
   at MyCompany.Dispositivos.InterfazDispositivos.ControlMosaico.icPanelViewer_MouseDown(Object sender, MouseEventArgs e)
   at System.Windows.Forms.Control.OnMouseDown(MouseEventArgs e)
   at System.Windows.Forms.UserControl.OnMouseDown(MouseEventArgs e)
   at MyCompany.Dispositivos.InterfazDispositivos.VisorDeMosaico.mousedown(Object sender, MouseEventArgs e)
   at System.Windows.Forms.Control.OnMouseDown(MouseEventArgs e)
   at System.Windows.Forms.UserControl.OnMouseDown(MouseEventArgs e)
   at MyCompany.BasicInterface.Controles_Basicos.ICLabel.lblText_MouseDown(Object sender, MouseEventArgs e)
   at System.Windows.Forms.Control.OnMouseDown(MouseEventArgs e)
   at System.Windows.Forms.Control.WmMouseDown(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.Label.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
Object reference not set to an instance of an object.
   at MyCompany.Dispositivos.Plugins.TICAnKorr.VisorTICAnKorrMini.MensajeEstado()
   at MyCompany.Dispositivos.Plugins.TICAnKorr.VisorTICAnKorrMini.m_DispositivoAsociado_NewResult(Object sender)
   at MyCompany.Dispositivos.ConexionesDispositivos.NewResultsEventHandler.Invoke(Object sender)
   at MyCompany.Dispositivos.ConexionesDispositivos.DeviceBase.OnNewResult()
   at MyCompany.Dispositivos.Plugins.TICAnKorr.DeviceTICAnKorr.HiloCaptura()
   at MyCompany.Dispositivos.ConexionesDispositivos.DeviceBase.<StartLive>b__9()
   at System.Threading.Tasks.Task.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()

我认为抛出的异常是这样的:

Object reference not set to an instance of an object.
       at MyCompany.Dispositivos.Plugins.TICAnKorr.VisorTICAnKorrMini.MensajeEstado()

真正的异常(exception)是什么？

如果这里不适合问这个问题，请告诉我，我会删除它。

我不是在问 Object reference not set to an instance of an object. 是什么意思，我知道，我是在问这是否是导致任务执行的异常抛出 System.Threading.Tasks.Task.ThrowIfExceptional。

Answer 1

当您执行返回 Task 的操作时，会发生什么异常情况会存储在任务的 Task.Exception 属性中。

当您调用 Wait 时，代码会等待任务完成，然后重新抛出 AggreagtedException 中发生的所有异常。因此，在任务完成后调用 ThrowIfExceptional 方法以引发任何已发生的异常。

很可能问题是执行任何代码以返回正在等待的任务的空引用。应该是里面的东西:

 MyCompany.Dispositivos.Plugins.TICAnKorr.DeviceTICAnKorr.StopLive()