内存泄露问题（高手进）

Question

CDC* pDC=GetDC();
CDC* dcMemory;
dcMemory = new CDC;
int R = 100;
int R1 = R - R/10; //内圈半径
    dcMemory->CreateCompatibleDC(pDC);
    CBitmap *Bitmap = new CBitmap;//重新创建BITMAP资源
Bitmap->CreateCompatibleBitmap(pDC,2*R,2*R);
CBitmap* map = dcMemory->SelectObject(Bitmap);
    //将位图选入自定义的设备中 dcMemory->FillSolidRect(0,0,2*R,2*R,RGB(166,202,240));
CPen RPen(PS_SOLID,1,RGB(0,0,0) );
CPen RPen1(PS_SOLID  , 2 , RGB(255,255,0));
CBrush RBrush(RGB(0,255,255));
dcMemory->SelectObject(RPen1);
dcMemory->Ellipse(0,0,2*R,2*R);
dcMemory->SelectObject(RPen);
dcMemory->Ellipse(R/10,R/10,2*R-R/10,2*R-R/10);
pDC->BitBlt(0,0,2*R,2*R,dcMemory,0,0, SRCCOPY);
Bitmap->DeleteObject();
map->DeleteObject();
RPen.DeleteObject();
RBrush.DeleteObject();
RPen1.DeleteObject();
dcMemory->DeleteDC();
delete dcMemory;
ReleaseDC(pDC);
pDC->DeleteDC();我不在ontime每一秒中调用这段代码，发现内存泄露。希望高手指教。

Answer 1

使用SelectObject后，还得用SelectObject选择原来的设备环境，否则会有内存泄露。
例如：
CPen *oldpen=pDC->SelectObject(&pen);
......
pDC->SelectObject(oldpen);