关于字符宽度，高度的一般处理

case WM_CREATE:
        hdc = GetDC(hwnd);
        GetTextMetrics(hdc, &tm);
        cxChar = tm.tmAveCharWidth;
        cxCaps = ((tm.tmPitchAndFamily) & 1 ? 3 : 2) * cxChar / 2;
        cyChar = tm.tmHeight + tm.tmExternalLeading;
        ReleaseDC(hwnd, hdc);
        return 0