求解哪里出了问题
`
/////////////////////////////////////////////////////////////////////////////
// CMyFirstView drawing
void CMyFirstView::OnDraw(CDC* pDC)
{
CMyFirstDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
// TODO: add draw code for native data here
CWnd *pDeskTop = GetDesktopWindow( );
CDC *pDC = pDeskTop->GetWindowDC( );
for ( int x = 0; x < 900; x++ );
for ( int y = 0; y < 700; y++ );
pDC->SetPixel( x+0, y+0, x*y );
pDeskTop->ReleaseDC( pDC );
}
/////////////////////////////////////////////////////////////////////////////
// CMyFirstView printing