How to update the dialog value inside a thread?(Visual C++)

[dperez79]

Threads Visual C++

Hi,
I am using several threads in my application, each thread can execute a global or a member function(static).
Now I can set the member variable value executing a function include in the App class. But I can't update the View ( UpdateData() is not possible in any function that belongs the thread).
Could you recommend me some way of update the dialog values inside the thread execution?
Thanks.

 

[Antharax]

Re: Threads Visual C++

Perhaps you could use messages

in the dialog thread add the parts to the cpp file:

// This should be declared somewhere, add only the ON_MESSAGE part!
BEGIN_MESSAGE_MAP(CFacManDlg, CDialog)
  //{{AFX_MSG_MAP(CFacManDlg)
  ON_WM_PAINT()
  //}}AFX_MSG_MAP
  ON_MESSAGE(WM_MY_MESSAGE, OnMyMessage)
END_MESSAGE_MAP()

// implementation of the OnMyMessage method!
LRESULT CMyDlg::OnMyMessage(WPARAM wParam, LPARAM lParam)
{
  // do whatever you want and use the wParam and the lParam if needed

  return 0; // I handled this message
}

In the header file of the dialog thread add the declaration of the method

protected:
  LRESULT OnMyMessage (WPARAM wParam, LPARAM lParam);
  ...

And create a header file with message ID's

#ifndef MyMessages_h_
#define MyMessages_h_

#include <windows.h>

#define WM_MY_MESSAGE(WM_USER + 100)

#endif //MyMessages_h_

Now you send messages from another thread like this in case you know your window's handle (hWnd_). :

SendMessage(hWnd_, WM_MY_MESSAGE, My_wParam, My_lParam);

You can pass the window handle to your thread's class by passing m_hWnd to your constructor from within the BOOL CMyDlg::OnInitDialog() method:

myThread_ = new myThread(m_hWnd);

Probably you can find other/better solutions for this too. Be creative ;-)

 

[MicKen]

Re: Threads Visual C++

One more Way,

If you want to refresh Dlg then pass the Handle of the Window(Dlg) to Thread or keep it global.

Using the Cwnd::Fromhandle() method create the local pointer to dlg and do the update.