NullReferenceException之谜

Question

由于某些原因，当我的应用程序启动时，我得到一个System.NullReferenceException。真的很奇怪，异常框是如何指向任何代码行的。我不知道是什么部分导致了这个问题。这是堆栈跟踪：

System.NullReferenceException was unhandled
 Message="Object reference not set to an instance of an object."
 Source="Microsoft.VisualBasic"
StackTrace:
   at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.MainFormLoadingDone(Object sender, EventArgs e)
   at System.EventHandler.Invoke(Object sender, EventArgs e)
   at System.Windows.Forms.Form.OnLoad(EventArgs e)
   at System.Windows.Forms.Form.OnCreateControl()
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl()
   at System.Windows.Forms.Control.WmShowWindow(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at System.Windows.Forms.ContainerControl.WndProc(Message& m)
   at System.Windows.Forms.Form.WmShowWindow(Message& m)
   at System.Windows.Forms.Form.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.SendMessage(HandleRef hWnd, Int32 msg, Int32 wParam, Int32 lParam)
   at System.Windows.Forms.Form.SetVisibleCore(Boolean value)
   at System.Windows.Forms.Control.set_Visible(Boolean value)
   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 EEMSReports.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()

有人以前见过这个或有什么建议吗？

提前致谢。

Answer 1

如果您希望能够在异常发生时调试应用程序，请创建一个项目，该项目将在启动调试器时启动应用程序（请参阅项目属性 - ＆gt; 调试 tab）。该项目不需要任何源代码。

然后，告诉调试器中断任何抛出的异常（请参阅调试 - ＆gt; 异常）并使用 F5 启动应用程序。

Answer 2

正如Ben在评论中所说，空引用来自：

EEMSReports.My.MyApplication.Main（String [] Args）in 17d14f5c-a337-4978-8281-53493378c1071.vb：第81行

这表示临时编译器生成的文件。从内存来看，这可能是C＃编译器中的一个错误，它会在尝试使用它之前删除临时文件。但我会设置Visual Studio来打破未处理的异常，然后查看抛出异常的位置。