研究好久才弄好，註釋的比較詳細，不明白的函式可以參考MSDN

  bool TransparentDIB(CBitmap * dib, /*要繪製的點陣圖*/ CDC * pDC, /*目標DC*/ CRect * rct, /*目標矩形*/ COLORREF transColor, /*透明色*/ bool bStretch /*是否拉伸點陣圖以適應目標矩形*/) { //驗證引數 if(dib == NULL || pDC == NULL || rct == NULL) return false; int nWidth; int nHeight; //點陣圖資訊物件 BITMAP w_bitmap_info; //獲取點陣圖資訊 dib->GetBitmap(&w_bitmap_info); //新建裝置上下文 CDC w_memoryDC; //建立相容記憶體DC w_memoryDC.CreateCompatibleDC(pDC); //根據拉伸狀態獲得影象實際繪製尺寸 if(bStretch) { nWidth = rct->Width(); nHeight = rct->Height(); } else { nWidth = w_bitmap_info.bmWidth; nHeight = w_bitmap_info.bmHeight; } w_memoryDC.SelectObject(dib);//選入點陣圖物件 w_memoryDC.SetBkColor(transColor);//設定透明色 CDC w_maskDC;//建立相容記憶體DC作為掩碼DC w_maskDC.CreateCompatibleDC(pDC);//建立相容記憶體DC作為掩碼DC CBitmap w_maskBitmap;//建立新點陣圖作為掩碼點陣圖 w_maskBitmap.CreateBitmap(w_bitmap_info.bmWidth,w_bitmap_info.bmHeight,1,1,NULL); //建立新點陣圖作為掩碼點陣圖 w_maskDC.SelectObject(&w_maskBitmap);//選入掩碼點陣圖 w_maskDC.BitBlt(0,0,w_bitmap_info.bmWidth,w_bitmap_info.bmHeight,&w_memoryDC,0,0,SRCCOPY); //SRCCOPY方式將源點陣圖以原始大小繪製到掩碼DC pDC->StretchBlt(0,0,nWidth,nHeight,&w_memoryDC,0,0,w_bitmap_info.bmWidth,w_bitmap_info.bmHeight,SRCINVERT); //SRCINVERT方式將源點陣圖拉伸繪製到視窗DC pDC->StretchBlt(0,0,nWidth,nHeight,&w_maskDC,0,0,w_bitmap_info.bmWidth,w_bitmap_info.bmHeight,SRCAND); //SRCAND方式將掩碼點陣圖拉伸繪製到視窗DC pDC->StretchBlt(0,0,nWidth,nHeight,&w_memoryDC,0,0,w_bitmap_info.bmWidth,w_bitmap_info.bmHeight,SRCINVERT); //SRCINVERT方式將源點陣圖拉伸繪製到視窗DC //完成繪製 w_memoryDC.DeleteDC();//刪除記憶體DC w_maskDC.DeleteDC();//刪除掩碼DC return true; }