DC

我知道用CWindowDC类的话 可以用CWindowDC(GetDesktopWindow);直接初始化\

如果用CDC的话~~怎么赋值 能在桌面绘图~

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HDC hDC = ::GetDC(NULL);// 可以直接操纵hDC   

CDC dc;   //   在屏幕中绘制

dc.Attach(hDC);

dc.SetBkMode(TRANSPARENT);

dc.SetTextColor(RGB(255,0,0));

CRect rect;

GetWindowRect(&rect);

//ScreenToClient(&rect);

ClientToScreen(&rect);

dc.TextOut(rect.top,rect.left,"sdf");

//dc.Detach();

//ReleaseDC(&dc);

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客户端的 DC

CClientDC dc(this);//  CClientDC  是CDC 的子类，在CClientDC  在构造时调用了Windows函数GetDC，在析构时调用了ReleaseDC

dc.SetBkMode(TRANSPARENT);

dc.SetTextColor(RGB(255,0,0));

CRect rect;

GetWindowRect(&rect);

//ScreenToClient(&rect);

// ClientToScreen(&rect);

// dc.TextOut(rect.top,rect.left,"sdf");

dc.TextOut(0,0,"sdf");