Use windows message to change text in CEdit with timeout control

When using socket class, usually you have to send your data received from remote peer to upper CDialog class, the basic ways are:
1, pass the windows handle (this or m_hWnd)to socket class object’s component data in construct function.
2, get the main window handle, use the function AfxGetApp()->m_pMainWnd;
3, use a globe buffer to contain data.

And there is an easy way pass data to upper class, just use the CEdit pointer.
The code is as follows: and we added time control.

HWND hWnd = NULL; //the CEdit component window handle if (NULL == m_pMsgCtrl) return false; if (NULL = (hWnd = m_pMsgCtrl->GetSafeHwnd())//CEdit *m_pMsgCtrl; return false; DWORD dwResult = 0; // the same as returned value of SendMessage // get the length of text in CEdit // 1000L stands for 1 second, up to 15 seconds if (SendMessageTimeout(hWnd, WM_GETTEXTLENGTH, 0, 0, SMTO_NORMAL, 1000L, &dwResult) != 0) { int nLen = (int) dwResult; // set the place to insert new string, just select the text. if (SendMessageTimeout(hWnd, EM_SETSEL, nLen, nLen, SMTO_NORMAL, 1000L, &dwResult) != 0) { // send new string if (SendMessageTimeout(hWnd, EM_REPLACESEL, FALSE, (LPARAM)strText, SMTO_NORMAL, 1000L, &dwResult) != 0) { } } }

It works the same as:

if (::IsWindow( m_pMsgCtrl->GetSafeHwnd() )) { int nLen = m_pMsgCtrl->GetWindowTextLength(); m_pMsgCtrl->SetSel(nLen, nLen); m_pMsgCtrl->ReplaceSel( strText ); }