CDC::StretchBlt
BOOL StretchBlt( int x, int y, int nWidth, int nHeight, CDC* pSrcDC, int xSrc, int ySrc, int nSrcWidth, int nSrcHeight, DWORD dwRop );CDC::SetStretchBltMode
int SetStretchBltMode( int nStretchMode );
BOOL StretchBlt( int x, int y, int nWidth, int nHeight, CDC* pSrcDC, int xSrc, int ySrc, int nSrcWidth, int nSrcHeight, DWORD dwRop );CDC::SetStretchBltMode
int SetStretchBltMode( int nStretchMode );
1变9,如此类推,如下示范
1 2 3 1 1 2 2 3 3
4 5 6 1 1 2 2 3 3
源图 4 4 5 5 6 6
4 4 5 5 6 6
等比放大1倍后的图