GetWindowText( hwndOutput, buf, outLength ) get existing text from edit control and put into buffer TCHAR * buf = ( TCHAR * ) GlobalAlloc( GPTR, outLength * sizeof(TCHAR) ) create buffer to hold current and new text Int outLength = GetWindowTextLength( hwndOutput ) + lstrlen(newText) + 1 get new length to determine buffer size HWND hwndOutput = GetDlgItem( hwnd, IDC_OUTPUT ) Try this: void AppendText( const HWND &hwnd, TCHAR *newText ) You are also leaking the memory that you allocate. You are also not allocating the buffer large enough to hold both the existing text and the new text being appended. If you are compiling for Unicode, TCHAR is 2 bytes, not 1 byte, but you are not taking that into account. Ix, iy, icx, icy, hwnd, (HMENU) ID_INFO, Global.GetWindowTextLength() returns the number of TCHAR elements in the text, but GlobalAlloc() expects a byte count instead. WS_BORDER | SS_LEFT | SS_SUNKEN | SS_WHITERECT, HwndInfo = CreateWindow ('static', NULL, WS_CHILD | WS_VISIBLE | SS_WHITERECT, tx, ty, tcx, tcy, hwnd, (HMENU) ID_TEXT, Global.hInstance, NULL) WS_BORDER | WS_HSCROLL | WS_VSCROLL | SS_LEFT | SS_SUNKEN | HwndText = CreateWindow ('static', NULL, WS_CHILD | WS_VISIBLE | For some reason it won't display the text no matter what I do - feed it an STL string (having it spit out a char *), a literal text string, or a regular char *. I looked at another instance of setting text in my program in a dialog window procedure, and it works fine. But nothing is displayed in the text boxes, and when I call GetWindowText() right after, I get a null string. The strings contain the correct text, and the handles are correct (I assume), according to the debugger. Hwnd is the handle to the parent window, and the sInfo/sText are STL string objects. SetWindowText (GetDlgItem (hwnd, ID_INFO), sInfo.c_str ())

SetWindowText (GetDlgItem (hwnd, ID_TEXT), sText.c_str ()) I am setting the text of a static text control in a normal window (not a dialog) with SetWindowText:

Getwindowtext to setwindow text