Net 2.0 - unbalanced stack

  • Thread starter Thread starter AlexS
  • Start date Start date
A

AlexS

Hi,

I migrated working 1.1 console project which worked to 2.0 having forms and
console window and started to get this exception in debugger
A call to PInvoke function 'Utils!Utils.ConsoleWindow::GetStdHandle' has
unbalanced the stack

This happens when I issue ShowWindow Win32 call from non-UI thread.

Strange thing it this works w/o any troubles in 1.1.

Main thread fails with cryptic

System.Reflection.TargetInvocationException: Exception has been thrown by
the target of an invocation. ---> System.InvalidOperationException:
Cross-thread operation not valid: Control '' accessed from a thread other
than the thread it was created on.

What should I do?
 
AlexS said:
I migrated working 1.1 console project which worked to 2.0 having forms and
console window and started to get this exception in debugger
A call to PInvoke function 'Utils!Utils.ConsoleWindow::GetStdHandle' has
unbalanced the stack

This happens when I issue ShowWindow Win32 call from non-UI thread.

Strange thing it this works w/o any troubles in 1.1.

Main thread fails with cryptic

System.Reflection.TargetInvocationException: Exception has been thrown by
the target of an invocation. ---> System.InvalidOperationException:
Cross-thread operation not valid: Control '' accessed from a thread other
than the thread it was created on.

What should I do?
Click to expand...

You need to only access UI elements from the thread which "owns" them -
typically the one which created them.
See http://www.pobox.com/~skeet/csharp/threads/winforms.shtml
 
Hi, Jon

I don't access UI elements from another thread - .Net maybe does. See main
thread exception - I have no controls with '' name

Initial exception in ShowWindow causes final crash with
A first chance exception of type
'System.Reflection.TargetInvocationException' occurred in mscorlib.dll

A first chance exception of type 'System.NullReferenceException' occurred in
System.Windows.Forms.dll

ShowWindow is Win32 API. As per debugger call which causes exception happens
on main UI thread - it's event handler for VisibleChanged

Any ideas?
 
By the way,

I did some more debugging and see now that ShowWindow returns ok, then
control goes somewhere inside framework and I get crash.

Please correct initial post: "this happens when I issue ShowWindow Win32
call from UI-thread"

Thx
Alex
 
AlexS said:
Hi,

I migrated working 1.1 console project which worked to 2.0 having
forms and console window and started to get this exception in debugger
A call to PInvoke function 'Utils!Utils.ConsoleWindow::GetStdHandle'
has unbalanced the stack

This happens when I issue ShowWindow Win32 call from non-UI thread.

Strange thing it this works w/o any troubles in 1.1.

Main thread fails with cryptic

System.Reflection.TargetInvocationException: Exception has been thrown
by the target of an invocation. ---> System.InvalidOperationException:
Cross-thread operation not valid: Control '' accessed from a thread
other than the thread it was created on.

What should I do?
Click to expand...

The windows handle you're passing to ShowWindow, who owns the handle? Is
it the Form that's making the call to ShowWindow? Is it some other
window?
 
Well, that means that you are passing a handle owned by the UI thread to
another thread, right?
Note that your code is wrong even in v1.x, in Windows it's wrong to use a
windows handle (guess StdHandle you pass to ShowWindow) from a thread that
doesn't own the handle.


Willy.
 
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