Exception has been thrown by the target of an invocation. (Backgroundworker)


  • i had encounter this error in the backgroundworker.progresschanged event. Anyone can help to fix this problem?

    the exception on the progresschanged event.


    System.Reflection.TargetInvocationException was unhandled
      Message="Exception has been thrown by the target of an invocation."
           at System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
           at System.RuntimeMethodHandle.InvokeMethodFast(Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
           at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)
           at System.Delegate.DynamicInvokeImpl(Object[] args)
           at System.Windows.Forms.Control.InvokeMarshaledCallbackDo(ThreadMethodEntry tme)
           at System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(Object obj)
           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)
           at System.Windows.Forms.Control.InvokeMarshaledCallback(ThreadMethodEntry tme)
           at System.Windows.Forms.Control.InvokeMarshaledCallbacks()
           at System.Windows.Forms.Control.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.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
           at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
           at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
           at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
           at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
           at System.Windows.Forms.Application.Run(ApplicationContext context)
           at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
           at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
           at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
           at PSMM_3.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
           at System.AppDomain.nExecuteAssembly(Assembly 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)
           at System.Threading.ThreadHelper.ThreadStart()

    Friday, September 14, 2007 12:22 PM


  • LonelyKnight,


    Based on your post, you have the System.Reflection.TargetInvocationException on backgroundworker.progresschanged event. I would like to provide you the suggestions as follows:


    1. Please take a look at the following KB article on the Exception issue:


    PRB: "System.Reflection.TargetInvocationException" Error Message When You Call the MethodInfo.Invoke Method

    When you load an assembly by using the Assembly.LoadFrom method, the common language runtime places the loaded assembly in the LoadFrom context of your application. Any probes for the dependencies of the assembly first probe the current application directory. If this probe fails, the common language runtime then probes the LoadFrom context of your application.


    You may load an assembly that has a simply-named dependency that has the same file name as a file in the current application directory. When you try to invoke a method in the loaded assembly by using the MethodInfo.Invoke method, and the invoked method uses the dependency, the common language runtime first probes the current directory path. When the common language runtime finds a file that has the same file name as the dependency, the probe stops. However, if this file does not have the same assembly identity as the dependency, the assembly bind fails, and the common language runtime generates a System.IO.FileLoadException error that is passed to the System.Reflection.TargetInvocationException error. Therefore, you may notice the behavior that is mentioned in the "Symptoms" section.


    2. Please use the InnerException to gets the Exception instance that caused the current exception. An instance of Exception that describes the error that caused the current exception. The InnerException property returns the same value as was passed into the constructor, or a null reference (Nothing in Visual Basic) if the inner exception value was not supplied to the constructor. This property is read-only.


    3. Please provide the related code snippet that cause the problem, but not only the event name. If you have any related questions, please also post the code snippet to help others to reproduce the exception on the problem. This will make your problem more clear and you will get the better support on the issue.


    Hope that can provide you some idea.

    Wednesday, September 19, 2007 6:49 AM