我使用DispatcherTimer
,因为我需要每隔几分钟进行一次操作。在此我调用BackgroundWorker
来完成我的工作,然后使用附加到计时器的调度程序来更新我的UI。我在想我得到的错误与计时器有关,但我不确定。调度员是完成的还是后台工作者?如何在foreach中进行ReportProgress?
错误:
这个操作已经有了 OperationCompleted呼吁它和 进一步的电话是非法的。
这样做:
(sender as BackgroundWorker).ReportProgress((counterTotalSteps / 100) * counterOnStep);
以下是简化版:
DispatcherTimer dispTimer = new DispatcherTimer();
Dispatcher dispatcher = dispTimer.Dispatcher;
dispTimer.Tick += delegate {dispTimer_Tick(dispatcher); };
dispTimer.Interval = new TimeSpan(0, 0, 45);
dispTimer.Start();
private void DoWork(object sender,Dispatcher dispatcher)
{
int counterTotalSteps = PartialEmployees.Count();
int counterOnStep = 1;
dispatcher.BeginInvoke(new Action(() =>
{
AllEmployees.Clear();
//calling the ReportProgress here works
foreach (var item in PartialEmployees)
{
counterOnStep ++;
//part below throws the error
(sender as BackgroundWorker).ReportProgress((counterTotalSteps / 100) * counterOnStep);
AllEmployees.Add(item);
}
counterOnStep = 0;
}));
}
修改 堆栈跟踪:
at System.ComponentModel.AsyncOperation.VerifyNotCompleted()
at System.ComponentModel.AsyncOperation.Post(SendOrPostCallback d, Object arg)
at System.ComponentModel.BackgroundWorker.ReportProgress(Int32 percentProgress, Object userState)
at System.ComponentModel.BackgroundWorker.ReportProgress(Int32 percentProgress)
at testDispatcher.ViewModel.EmployeeListViewModel.<>c__DisplayClass7.<DoWork>b__6() in C:\Users\kozaj\Documents\Visual Studio 2010\Projects\testDispatcher\testDispatcher\ViewModel\EmployeeListViewModel.cs:line 91
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.DispatcherOperation.InvokeImpl()
at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
at System.Threading.ExecutionContext.runTryCode(Object userData)
at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Windows.Threading.DispatcherOperation.Invoke()
at System.Windows.Threading.Dispatcher.ProcessQueue()
at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
at System.Windows.Threading.Dispatcher.Run()
at System.Windows.Application.RunDispatcher(Object ignore)
at System.Windows.Application.RunInternal(Window window)
at System.Windows.Application.Run(Window window)
at System.Windows.Application.Run()
at testDispatcher.App.Main() in C:\Users\kozaj\Documents\Visual Studio 2010\Projects\testDispatcher\testDispatcher\obj\x86\Debug\App.g.cs:line 50
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
答案 0 :(得分:3)
事件顺序
我建议仅在实际具有UI交互的步骤中使用dispatcher.Invoke(立即运行它)。
答案 1 :(得分:1)
由于您的工作是在UI线程上完成的,因此您根本不应使用BackgroundWorker。
相反,您应该直接在循环内更新进度条。