C＃NullReferenceException，但我不知道是什么原因引起的

Question

I get a NullRefrenceException once in a while (it happens maybe one out of ten times) when I drop an object on a RadChart (from the Telerik-components).

Now I'd like to know which object is causing the Exception, but I don't really understand which one it is from just looking at the StackTrace.

That's the stack-trace:

bei System.Windows.Controls.VirtualizingStackPanel.BringIndexIntoView(Int32 index)
bei System.Windows.Controls.ItemsControl.OnBringItemIntoView(Object arg)
bei System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
bei MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
bei System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
bei System.Windows.Threading.DispatcherOperation.InvokeImpl()
bei System.Threading.ExecutionContext.runTryCode(Object userData)
bei System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
bei System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
bei System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
bei System.Windows.Threading.DispatcherOperation.Invoke()
bei System.Windows.Threading.Dispatcher.ProcessQueue()
bei System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
bei MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
bei MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
bei System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
bei MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
bei System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
bei System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
bei MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
bei MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
bei System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
bei System.Windows.Application.RunInternal(Window window)
bei System.Windows.Application.Run()
bei Filiale_der_Zukunft.App.Main() in D:\oberflaeche-der-zukunft\TP_IT\Prototyp\Filiale der Zukunft\obj\Debug\App.g.cs:Zeile 0.
bei System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
bei Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
bei System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
bei System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
bei System.Threading.ThreadHelper.ThreadStart()

Answer 1

Nothing in your StackTrace shows the Telerik RadControl. Looking att the top of the stacktrace it seems that you try to show an element that is not yet created.