为什么设置了画笔的颜色无效?
我在 HDC 设置了画笔的颜色,为什么绘图出来的还是黑色的画笔?
请看我的代码:
HDC hdcSrc,hdcDest;
HWND hwndDest;
POINT* ptTemp = (0, 0);
HPEN* oldPen;
HPEN newPen;
// 获得场景窗口的句柄
hwndDest = (HWND)CpThis->m_ViewhWnd;
// 显示图片
hdcDest = ::GetDC( hwndDest );
hdcSrc = ::CreateCompatibleDC( hdcDest );
::SelectObject( hdcSrc, CpThis->hBmp );
::BitBlt(hdcDest,
0,0,320,240,
hdcSrc,
0,0,
SRCCOPY );
// 创建白色的画笔
newPen = ::CreatePen(PS_SOLID, 1, RGB(255, 255, 255));
oldPen = (HPEN*)::SelectObject( hdcDest, &newPen);
// 绘制标准取像框
::MoveToEx( hdcDest, 70, 10, ptTemp);
::LineTo( hdcDest, 70 + 179, 10);
::LineTo( hdcDest, 70 + 179, 10 + 221);
::LineTo( hdcDest, 70, 10 + 221);
::LineTo( hdcDest, 70, 10);
::SelectObject( hdcDest, oldPen );
::DeleteObject(newPen);
::DeleteDC( hdcSrc );
::ReleaseDC( hwndDest, hdcDest );