Re: Text color in Win32 program
"CN99" <leon800219@yahoo.com.cn> wrote in message
news:e55cm6$509$1@news.cn99.com...
I just can't see why the following code doesn't change the text color to
red.
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM
lParam)
{
HDC hdc = ::GetDC(hwnd);
HPEN pen = ::CreatePen(PS_SOLID, 3, RGB(255, 0, 0));
HGDIOBJ old;
old = ::SelectObject(&hdc, pen);
switch (message)
{
case WM_DESTROY:
PostQuitMessage (0) ;
return 0 ;
case WM_LBUTTONDOWN:
::TextOut(hdc, 100, 100, TEXT("Hello Windows"), 13);
::SelectObject(hdc, old);
return 0;
}
ReleaseDC (hwnd, hdc) ;
return ::DefWindowProc (hwnd, message, wParam, lParam) ;
}
TextOut, "writes a character string at the specified location, using the
currently selected font, background color, and text color". It doesn't use
or care about the currently selected pen. You need to use SetTextColor
and/or SetBkColor. Note that you GetDC and CreatePen for every single
message and only use them in response to a single message -- that's just
unnecessarily wasteful. That you never do a DeleteObject on your CreatePen
means that you will quickly exhaust the availability of GDI resources --
that's just wrong. As a general rule, you should paint only in response to
WM_PAINT.
--
Jeff Partch [VC++ MVP]