在第二个 UI 线程上使用命令时出现 InvalidOperationException
InvalidOperationException when using a command on a second UI thread
我们正在向我们的 catel 4.4.0 MVVM 应用程序添加第二个 UI 线程。
我已经在第二个 UI 线程上创建了我的视图和视图模型，并且正在使用 DispatcherTimer 定期更新视图模型。那部分似乎工作正常。但是，当我在视图模型的构造函数中创建 Catel.MVVM.Command 时，我 运行 遇到了问题。当命令的 CanExecute 触发时，我在第二个 UI 线程上得到一个 System.InvalidOperationException。
命令没什么特别的。
private bool ImageClickCanExecute()
{
return true;
}
public void ImageClickAction()
{
if(ImageClickTarget != null)
Process.Start(ImageClickTarget.ToString());
}
观点也不是。
<Grid>
<Button Command="{Binding ImageClickCommand}">
<Image Name="ImageSource" Source="{Binding ImageSource, FallbackValue={x:Null}}"/>
</Button>
</Grid>
堆栈跟踪如下。
0:010> !PrintException /d 00000282cb8effd0
Exception object: 00000282cb8effd0
Exception type: System.Reflection.TargetInvocationException
Message: Exception has been thrown by the target of an invocation.
InnerException: System.InvalidOperationException, Use !PrintException 00000282cb8edee8 to see more.
StackTrace (generated):
SP IP Function
000000B0459FD510 0000000000000000 mscorlib_ni!System.RuntimeMethodHandle.InvokeMethod(System.Object, System.Object[], System.Signature, Boolean)+0x1
000000B0459FD510 00007FFFCC5E1C20 mscorlib_ni!System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(System.Object, System.Object[], System.Object[])+0x80
000000B0459FD580 00007FFFCC5BE789 mscorlib_ni!System.Delegate.DynamicInvokeImpl(System.Object[])+0x99
000000B0459FD5D0 00007FFF70FC83AE UNKNOWN!Catel.EventHandlerExtensions.SplitInvoke(System.Delegate, System.Object[])+0xfe
000000B0459FD630 00007FFF7164E085 UNKNOWN!Catel.EventHandlerExtensions.SafeInvoke(System.EventHandler, System.Object, System.EventArgs)+0x55
000000B0459FD680 00007FFF71674998 UNKNOWN!Catel.MVVM.Command`2+<<RaiseCanExecuteChanged>b__32_0>d[[System.__Canon, mscorlib],[System.__Canon, mscorlib]].MoveNext()+0x38
000000B0459FD7B0 00007FFFCD2E1224 mscorlib_ni!System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(System.Threading.Tasks.Task)+0xd3f9c4
000000B0459FD7F0 00007FFFCC5A17AD mscorlib_ni!System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(System.Threading.Tasks.Task)+0x3d
000000B0459FD820 00007FFF71674515 UNKNOWN!Catel.MVVM.Command`2+<>c__DisplayClass35_0+<<AutoDispatchIfRequiredAsync>b__0>d[[System.__Canon, mscorlib],[System.__Canon, mscorlib]].MoveNext()+0xf5
000000B0459FD9B0 00007FFFCCFCDA88 mscorlib_ni!System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0(System.Object)+0x38
000000B0459FD9E0 00007FFFA8119C0E WindowsBase_ni!System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)+0xae
000000B0459FDA50 00007FFFA8119AC6 WindowsBase_ni!System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)+0x36
000000B0459FDAA0 00007FFFA811CA2B WindowsBase_ni!System.Windows.Threading.DispatcherOperation.InvokeImpl()+0x10b
000000B0459FDB20 00007FFFCC5CA79E mscorlib_ni!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)+0x15e
000000B0459FDBF0 00007FFFCC5CA637 mscorlib_ni!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)+0x17
000000B0459FDC20 00007FFFCC5CA5F2 mscorlib_ni!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)+0x52
000000B0459FDC70 00007FFFA8333810 WindowsBase_ni!MS.Internal.CulturePreservingExecutionContext.Run(MS.Internal.CulturePreservingExecutionContext, System.Threading.ContextCallback, System.Object)+0x80
000000B0459FDCD0 00007FFFA811C784 WindowsBase_ni!System.Windows.Threading.DispatcherOperation.Invoke()+0x64
000000B0459FDD30 00007FFFA8117C24 WindowsBase_ni!System.Windows.Threading.Dispatcher.ProcessQueue()+0x1a4
000000B0459FDDB0 00007FFFA8118061 WindowsBase_ni!System.Windows.Threading.Dispatcher.WndProcHook(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)+0x71
000000B0459FDE30 00007FFFA8119E53 WindowsBase_ni!MS.Win32.HwndWrapper.WndProc(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)+0xc3
000000B0459FDEC0 00007FFFA8119D82 WindowsBase_ni!MS.Win32.HwndSubclass.DispatcherCallbackOperation(System.Object)+0x82
000000B0459FDF10 00007FFFA8119BC9 WindowsBase_ni!System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)+0x69
000000B0459FDF80 00007FFFA8119AC6 WindowsBase_ni!System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)+0x36
000000B0459FDFD0 00007FFFA8117583 WindowsBase_ni!System.Windows.Threading.Dispatcher.LegacyInvokeImpl(System.Windows.Threading.DispatcherPriority, System.TimeSpan, System.Delegate, System.Object, Int32)+0x173
000000B0459FE070 00007FFFA81194FF WindowsBase_ni!MS.Win32.HwndSubclass.SubclassWndProc(IntPtr, Int32, IntPtr, IntPtr)+0x11f
000000B0459FE390 0000000000000000 WindowsBase_ni!MS.Win32.UnsafeNativeMethods.DispatchMessage(System.Windows.Interop.MSG ByRef)+0x1
000000B0459FE450 00007FFFA812D8FC WindowsBase_ni!System.Windows.Threading.Dispatcher.PushFrameImpl(System.Windows.Threading.DispatcherFrame)+0xec
000000B0459FE4E0 00007FFFA26A98B3 PresentationFramework_ni!System.Windows.Application.RunDispatcher(System.Object)+0x73
000000B0459FE520 00007FFFA26A969D PresentationFramework_ni!System.Windows.Application.RunInternal(System.Windows.Window)+0x8d
000000B0459FE580 00007FFF70FD70F7 UNKNOWN!xxx.Wpf.App.Main()+0x67
000000B0459FF0C0 0000000000000000 mscorlib_ni!System.AppDomain._nExecuteAssembly(System.Reflection.RuntimeAssembly, System.String[])+0x1
000000B0459FF0C0 00007FFFCCD57EBF mscorlib_ni!System.AppDomain.ExecuteAssembly(System.String, System.Security.Policy.Evidence, System.String[])+0x7f
000000B0459FF110 00007FFF7053434E UNKNOWN!Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()+0x3e
000000B0459FF150 00007FFFCC5CA79E mscorlib_ni!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)+0x15e
000000B0459FF220 00007FFFCC5CA637 mscorlib_ni!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)+0x17
000000B0459FF250 00007FFFCC5CA5F2 mscorlib_ni!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)+0x52
000000B0459FF2A0 00007FFFCC51BEF2 mscorlib_ni!System.Threading.ThreadHelper.ThreadStart()+0x52
StackTraceString: <none>
HResult: 80131604
0:010> !PrintException /d 00000282cb8edee8
Exception object: 00000282cb8edee8
Exception type: System.InvalidOperationException
Message: The calling thread cannot access this object because a different thread owns it.
InnerException: <none>
StackTrace (generated):
SP IP Function
000000B0459FCD70 00007FFFA8446977 WindowsBase_ni!System.Windows.Threading.Dispatcher.VerifyAccess()+0x32faf7
000000B0459FCDA0 00007FFFA8112806 WindowsBase_ni!System.Windows.DependencyObject.GetValue(System.Windows.DependencyProperty)+0x26
000000B0459FCE00 00007FFFA27EBB5B PresentationFramework_ni!System.Windows.Controls.Primitives.ButtonBase.get_Command()+0x2b
000000B0459FCE30 00007FFFA27EBB00 PresentationFramework_ni!System.Windows.Controls.Primitives.ButtonBase.UpdateCanExecute()+0x10
StackTraceString: <none>
HResult: 80131509
这是因为，默认情况下，命令会使用 DispatcherService 自动发送更改通知。由于您是 运行 边缘情况（2 ui 线程），我建议您关闭自动调度并自行处理。
由于这是一个静态保护成员，您需要从 CommandBase 派生您自己的命令 class 并将 AutomaticallyDispatchEvents 设置为 false。
ps。我建议使用 IProcessService 而不是直接使用 Process.Start，它允许您在需要时模拟或替换它。
我们正在向我们的 catel 4.4.0 MVVM 应用程序添加第二个 UI 线程。
我已经在第二个 UI 线程上创建了我的视图和视图模型，并且正在使用 DispatcherTimer 定期更新视图模型。那部分似乎工作正常。但是，当我在视图模型的构造函数中创建 Catel.MVVM.Command 时，我 运行 遇到了问题。当命令的 CanExecute 触发时，我在第二个 UI 线程上得到一个 System.InvalidOperationException。
命令没什么特别的。
private bool ImageClickCanExecute()
{
return true;
}
public void ImageClickAction()
{
if(ImageClickTarget != null)
Process.Start(ImageClickTarget.ToString());
}
观点也不是。
<Grid>
<Button Command="{Binding ImageClickCommand}">
<Image Name="ImageSource" Source="{Binding ImageSource, FallbackValue={x:Null}}"/>
</Button>
</Grid>
堆栈跟踪如下。
0:010> !PrintException /d 00000282cb8effd0
Exception object: 00000282cb8effd0
Exception type: System.Reflection.TargetInvocationException
Message: Exception has been thrown by the target of an invocation.
InnerException: System.InvalidOperationException, Use !PrintException 00000282cb8edee8 to see more.
StackTrace (generated):
SP IP Function
000000B0459FD510 0000000000000000 mscorlib_ni!System.RuntimeMethodHandle.InvokeMethod(System.Object, System.Object[], System.Signature, Boolean)+0x1
000000B0459FD510 00007FFFCC5E1C20 mscorlib_ni!System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(System.Object, System.Object[], System.Object[])+0x80
000000B0459FD580 00007FFFCC5BE789 mscorlib_ni!System.Delegate.DynamicInvokeImpl(System.Object[])+0x99
000000B0459FD5D0 00007FFF70FC83AE UNKNOWN!Catel.EventHandlerExtensions.SplitInvoke(System.Delegate, System.Object[])+0xfe
000000B0459FD630 00007FFF7164E085 UNKNOWN!Catel.EventHandlerExtensions.SafeInvoke(System.EventHandler, System.Object, System.EventArgs)+0x55
000000B0459FD680 00007FFF71674998 UNKNOWN!Catel.MVVM.Command`2+<<RaiseCanExecuteChanged>b__32_0>d[[System.__Canon, mscorlib],[System.__Canon, mscorlib]].MoveNext()+0x38
000000B0459FD7B0 00007FFFCD2E1224 mscorlib_ni!System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(System.Threading.Tasks.Task)+0xd3f9c4
000000B0459FD7F0 00007FFFCC5A17AD mscorlib_ni!System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(System.Threading.Tasks.Task)+0x3d
000000B0459FD820 00007FFF71674515 UNKNOWN!Catel.MVVM.Command`2+<>c__DisplayClass35_0+<<AutoDispatchIfRequiredAsync>b__0>d[[System.__Canon, mscorlib],[System.__Canon, mscorlib]].MoveNext()+0xf5
000000B0459FD9B0 00007FFFCCFCDA88 mscorlib_ni!System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0(System.Object)+0x38
000000B0459FD9E0 00007FFFA8119C0E WindowsBase_ni!System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)+0xae
000000B0459FDA50 00007FFFA8119AC6 WindowsBase_ni!System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)+0x36
000000B0459FDAA0 00007FFFA811CA2B WindowsBase_ni!System.Windows.Threading.DispatcherOperation.InvokeImpl()+0x10b
000000B0459FDB20 00007FFFCC5CA79E mscorlib_ni!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)+0x15e
000000B0459FDBF0 00007FFFCC5CA637 mscorlib_ni!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)+0x17
000000B0459FDC20 00007FFFCC5CA5F2 mscorlib_ni!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)+0x52
000000B0459FDC70 00007FFFA8333810 WindowsBase_ni!MS.Internal.CulturePreservingExecutionContext.Run(MS.Internal.CulturePreservingExecutionContext, System.Threading.ContextCallback, System.Object)+0x80
000000B0459FDCD0 00007FFFA811C784 WindowsBase_ni!System.Windows.Threading.DispatcherOperation.Invoke()+0x64
000000B0459FDD30 00007FFFA8117C24 WindowsBase_ni!System.Windows.Threading.Dispatcher.ProcessQueue()+0x1a4
000000B0459FDDB0 00007FFFA8118061 WindowsBase_ni!System.Windows.Threading.Dispatcher.WndProcHook(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)+0x71
000000B0459FDE30 00007FFFA8119E53 WindowsBase_ni!MS.Win32.HwndWrapper.WndProc(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)+0xc3
000000B0459FDEC0 00007FFFA8119D82 WindowsBase_ni!MS.Win32.HwndSubclass.DispatcherCallbackOperation(System.Object)+0x82
000000B0459FDF10 00007FFFA8119BC9 WindowsBase_ni!System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)+0x69
000000B0459FDF80 00007FFFA8119AC6 WindowsBase_ni!System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)+0x36
000000B0459FDFD0 00007FFFA8117583 WindowsBase_ni!System.Windows.Threading.Dispatcher.LegacyInvokeImpl(System.Windows.Threading.DispatcherPriority, System.TimeSpan, System.Delegate, System.Object, Int32)+0x173
000000B0459FE070 00007FFFA81194FF WindowsBase_ni!MS.Win32.HwndSubclass.SubclassWndProc(IntPtr, Int32, IntPtr, IntPtr)+0x11f
000000B0459FE390 0000000000000000 WindowsBase_ni!MS.Win32.UnsafeNativeMethods.DispatchMessage(System.Windows.Interop.MSG ByRef)+0x1
000000B0459FE450 00007FFFA812D8FC WindowsBase_ni!System.Windows.Threading.Dispatcher.PushFrameImpl(System.Windows.Threading.DispatcherFrame)+0xec
000000B0459FE4E0 00007FFFA26A98B3 PresentationFramework_ni!System.Windows.Application.RunDispatcher(System.Object)+0x73
000000B0459FE520 00007FFFA26A969D PresentationFramework_ni!System.Windows.Application.RunInternal(System.Windows.Window)+0x8d
000000B0459FE580 00007FFF70FD70F7 UNKNOWN!xxx.Wpf.App.Main()+0x67
000000B0459FF0C0 0000000000000000 mscorlib_ni!System.AppDomain._nExecuteAssembly(System.Reflection.RuntimeAssembly, System.String[])+0x1
000000B0459FF0C0 00007FFFCCD57EBF mscorlib_ni!System.AppDomain.ExecuteAssembly(System.String, System.Security.Policy.Evidence, System.String[])+0x7f
000000B0459FF110 00007FFF7053434E UNKNOWN!Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()+0x3e
000000B0459FF150 00007FFFCC5CA79E mscorlib_ni!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)+0x15e
000000B0459FF220 00007FFFCC5CA637 mscorlib_ni!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)+0x17
000000B0459FF250 00007FFFCC5CA5F2 mscorlib_ni!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)+0x52
000000B0459FF2A0 00007FFFCC51BEF2 mscorlib_ni!System.Threading.ThreadHelper.ThreadStart()+0x52
StackTraceString: <none>
HResult: 80131604
0:010> !PrintException /d 00000282cb8edee8
Exception object: 00000282cb8edee8
Exception type: System.InvalidOperationException
Message: The calling thread cannot access this object because a different thread owns it.
InnerException: <none>
StackTrace (generated):
SP IP Function
000000B0459FCD70 00007FFFA8446977 WindowsBase_ni!System.Windows.Threading.Dispatcher.VerifyAccess()+0x32faf7
000000B0459FCDA0 00007FFFA8112806 WindowsBase_ni!System.Windows.DependencyObject.GetValue(System.Windows.DependencyProperty)+0x26
000000B0459FCE00 00007FFFA27EBB5B PresentationFramework_ni!System.Windows.Controls.Primitives.ButtonBase.get_Command()+0x2b
000000B0459FCE30 00007FFFA27EBB00 PresentationFramework_ni!System.Windows.Controls.Primitives.ButtonBase.UpdateCanExecute()+0x10
StackTraceString: <none>
HResult: 80131509
这是因为，默认情况下，命令会使用 DispatcherService 自动发送更改通知。由于您是 运行 边缘情况（2 ui 线程），我建议您关闭自动调度并自行处理。
由于这是一个静态保护成员，您需要从 CommandBase 派生您自己的命令 class 并将 AutomaticallyDispatchEvents 设置为 false。
ps。我建议使用 IProcessService 而不是直接使用 Process.Start，它允许您在需要时模拟或替换它。