"Ayrton Phoenix da silva" wrote:

> Dear all,
>
> In my winForm, when user select QUIT, and I will use multi threading to save
> user information and then close the application.  Sometime it will throw
> 'Object reference not set to an instance of an object.'  I'm the following
> error fairly often (but randomly), and I can't
> figure out why it is happening.  Any ideas?
>
> Object reference not set to an instance of an object.
> System.NullReferenceException: Object reference not set to an instance of an
> object.
>    at System.Windows.Forms.UnsafeNativeMethods.CallWindowProc(IntPtr
> wndProc, IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
>    at System.Windows.Forms.NativeWindow.DefWndProc(Message& m)
>    at System.Windows.Forms.Control.DefWndProc(Message& m)
>    at System.Windows.Forms.Control.WmUpdateUIState(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.ParkingWindow.WndProc(Message& m)
>    at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
>    at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
>    at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg,
> IntPtr wparam, IntPtr lparam)
>
>
>

"Herfried K. Wagner [MVP]" wrote:

> "Ayrton Phoenix da silva" <phoe***@flex-logic.com> schrieb:
> > In my winForm, when user select QUIT, and I will use multi threading to
> > save user information and then close the application.  Sometime it will
> > throw 'Object reference not set to an instance of an object.'  I'm the
> > following error fairly often (but randomly), and I can't
> > figure out why it is happening.  Any ideas?
>
> Are you sure you are not accessing Windows Forms controls'/forms' instance
> members directly from within your threads?
>
> --
>  M S   Herfried K. Wagner
> M V P  <URL:http://dotnet.mvps.org/>
>  V B   <URL:http://dotnet.mvps.org/dotnet/faqs/>
>
>

"Herfried K. Wagner [MVP]" wrote:

> "Serg" <S***@discussions.microsoft.com> schrieb:
> >I thought the companies would be more selective in hiring these days...
>
> ?!?
>
> --
>  M S   Herfried K. Wagner
> M V P  <URL:http://dotnet.mvps.org/>
>  V B   <URL:http://dotnet.mvps.org/dotnet/faqs/>
>

"Ayrton Phoenix da silva" <phoe***@flex-logic.com> wrote in message
news:e5XJz3Q0EHA.2676@TK2MSFTNGP12.phx.gbl...
> Dear all,
>
> In my winForm, when user select QUIT, and I will use multi threading to
> save user information and then close the application.  Sometime it will
> throw 'Object reference not set to an instance of an object.'  I'm the
> following error fairly often (but randomly), and I can't
> figure out why it is happening.  Any ideas?
>
> Object reference not set to an instance of an object.
> System.NullReferenceException: Object reference not set to an instance of
> an object.
>   at System.Windows.Forms.UnsafeNativeMethods.CallWindowProc(IntPtr
> wndProc, IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
>   at System.Windows.Forms.NativeWindow.DefWndProc(Message& m)
>   at System.Windows.Forms.Control.DefWndProc(Message& m)
>   at System.Windows.Forms.Control.WmUpdateUIState(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.ParkingWindow.WndProc(Message& m)
>   at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
>   at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
>   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg,
> IntPtr wparam, IntPtr lparam)
>
>