为什么不能在cview上正确画图。

Question

我在cview上显示了一张dib位图，然后又在其上面画几个方框标识这张图。但有些方框却画不出来，这是为什么？以下上程序。
        CClentDC *clientDC = new CClientDC(pView)//pView 就是CView对象。
CRgn reign;
CBrush brush( RGB(0,0,255) ); reign.CreateRectRgn(120,135,150,150);
clientDC->FrameRgn ( &reign,&brush,2,2);
reign.DeleteObject(); reign.CreateRectRgn(240,120,270,135);
clientDC->FrameRgn ( &reign,&brush,2,2);
reign.DeleteObject(); reign.CreateRectRgn(240,150,270,165);
clientDC->FrameRgn ( &reign,&brush,2,2);
reign.DeleteObject(); reign.CreateRectRgn(210,0,240,15);
clientDC->FrameRgn ( &reign,&brush,2,2);
reign.DeleteObject(); reign.CreateRectRgn(240,135,270,150);
clientDC->FrameRgn ( &reign,&brush,2,2);
reign.DeleteObject();
delete clientDC;

Answer 1

在OnDraw(CDC* pDC)函数里画可以，我帮你试过：         CClientDC *clientDC = new CClientDC(this);//pView 就是CView对象。
CRgn reign;
CBrush brush( RGB(0,0,255) ); reign.CreateRectRgn(120,135,150,150);
clientDC->FrameRgn ( &reign,&brush,2,2);
reign.DeleteObject(); reign.CreateRectRgn(240,120,270,135);
clientDC->FrameRgn ( &reign,&brush,2,2);
reign.DeleteObject(); reign.CreateRectRgn(240,150,270,165);
clientDC->FrameRgn ( &reign,&brush,2,2);
reign.DeleteObject(); reign.CreateRectRgn(210,0,240,15);
clientDC->FrameRgn ( &reign,&brush,2,2);
reign.DeleteObject(); reign.CreateRectRgn(240,135,270,150);
clientDC->FrameRgn ( &reign,&brush,2,2);
reign.DeleteObject();
delete clientDC;

Answer 2

最好在ondraw里面画。其他地方，有可能被你误擦除了。

Answer 3

在OnDraw函数里画，不然被OnDraw函数覆盖了