VC6.0中的畫圖問題

我的做法是，將pictrue控件的ID改下 比如IDC_MY;

CDC *dc=GetDlgItem(IDC_MY)->GetDC();

CPen MyPen,*OldPen;

MyPen.CreatePen(PS_SOLID,1,RGB(255,0,0));

OldPen = dc->SelectObject(&MyPen);

dc->MoveTo(20,30);

dc->LineTo(200,300);

dc->SelectObject(OldPen);

MyPen.DeleteObject();

ReleaseDC(dc);