Re: sending CString to CStatic label control from worker thread
Z.K. wrote:
I need to send a CString from a thread to a static label on the main
dialog form. I think I have the thread working okay, but I am unsure
how to send the CString to the dialog control. I have seen information
on using PostMessage and SendMessage, but I don't really understand how
to use these functions.
Obviously I can't do like I tried below and I can't get a pointer to the
control from the thread function, so just how do I say send the word
"hello" to the SetWindowText() function of the label control on the
dialog form. I have looked on the Internet and in several books, but I
still don't quite understand without an exact example of how to do this.
It seems like all that PostMessage can do is say repaint the screen and
other simple tasks, but how do I do something with an individual control.
Z.K.
--------------------------------------
CWinThread* pThread =
AfxBeginThread(WorkerThreadProc,this,THREAD_PRIORITY_NORMAL,0,0,NULL);
MessageBox("Thread Started");
UINT CInterfaceKitTestDlg::WorkerThreadProc( LPVOID Param )
{
CString temp;
CPhidgetServoHandle Servo = 0;
double motorPos = 0.0;
CInterfaceKitTestDlg * pTest = (CInterfaceKitTestDlg *)Param;
pTest->PostMessage(IDC_INPUT,"hello"); //just an example
of //what I would
//like to do, unsure of how.
//this is not meant to be a
//real statement.
CPhidgetServo_getMotorPosition(Servo,0,&motorPos);
temp.Format("Motor Position 0 = %f",motorPos);
AfxMessageBox(temp);
//m_input.SetWindowText(temp);
return TRUE;
}
Z.K.:
If you post or send a custom mesage to the dialog itself, then in the
handler you can do anything you want, including setting the text of a
control.
In MyDialog.h:
Define message:
#define UM_MY_MESSAGE WM_APP+1
Prototype:
afx_msg LRESULT OnMyMessage(WPARAM wParam, LPARAM lParam);
In MyDialog.cpp:
Message map entry:
ON_MESSAGE(UM_MY_MESSAGE, OnMyMessage)
Usage:
CMyDialog* pDlg =(CMyDialog*)pParam;
LPCTSTR msg = _T("Hello");
pDlg->PostMessage(UM_MY_MESSAGE, (WPARAM)msg);
Handler:
LRESULT CMyDialog::OnMyMessage(WPARAM wParam, LPARAM lParam)
{
LPCTSTR msg = (LPCTSTR)wParam;
GetDlgItem(IDC_INPUT)->SetWindowText(msg);
return 1;
}
Try it!
David Wilkinson