C++ 透明位图

在开发界面及棋牌游戏过程中，需要很多镂空的图片,而且图片形式一般比较固定.

所以封装了几种常见的镂空方法.

1. 用于没有掩码图,只有指定透明色,不进行伸缩

void DrawTransBitmap( HDC hdcDest,            // 目标DC
                                            int nXOriginDest,       // 目标X偏移
                                            int nYOriginDest,       // 目标Y偏移
                                            int nWidthDest,          // 目标宽度
                                            int nHeightDest,        // 目标高度
                                            HDC hdcSrc,              // 源DC
                                            int nXOriginSrc,         // 源X起点
                                            int nYOriginSrc,         // 源Y起点
                                            COLORREF crTransparent // 透明色,COLORREF类型
                                        );

适用图片:

2. 用于没有掩码图,只有指定透明色,可以进行伸缩

 void DrawTransBitmap( HDC hdcDest,       // 目标DC
                                             int nXOriginDest,   // 目标X偏移
                                             int nYOriginDest,   // 目标Y偏移
                                             int nWidthDest,      // 目标宽度
                                             int nHeightDest,    // 目标高度
                                             HDC hdcSrc,          // 源DC
                                             int nXOriginSrc,     // 源X起点
                                             int nYOriginSrc,     // 源Y起点
                                             int nWidthSrc,        // 源宽度
                                             int nHeightSrc,      // 源高度
                                             COLORREF crTransparent  // 透明色,COLORREF类型
      );

适用图片:同1,可拉伸

3.指定掩码图,和掩码图属于不同图片

 void DrawTransBitmap( HDC hdcDest,        // 目标DC
                                             int nXOriginDest,    // 目标X偏移
                                             int nYOriginDest,    // 目标Y偏移
                                             int nWidthDest,       // 目标宽度
                                             int nHeightDest,     // 目标高度
                                             HDC hdcSrc,          // 源DC
                                             HDC hdcMask,       //掩码DC
                                             int nXOriginSrc,     // 源X起点
                                             int nYOriginSrc,     // 源Y起点
                                            COLORREF crTransparent  // 透明色,COLORREF类型
                                          );

适用图片:  和

4.指定图片和掩码图同属于一张图片

void DrawTransBitmap(HDC hDC, 
                                           int nPosX, 
                                           int nPosY,
                                           int nCX, 
                                           int nCY, 
                                           HBITMAP hObj

                                           );

适用图片:

5.得到位图HRGN

   HRGN CreateBitmapRgn(int nWidth,int nHeight,HBITMAP hbmp,COLORREF cTrans);

适用图片:

以下是完整代码

 

//用于没有掩码图,只有指定透明色,不进行伸缩
//方法一：
void DrawTransBitmap( HDC hdcDest,      // 目标DC
                    int nXOriginDest,   // 目标X偏移
                    int nYOriginDest,   // 目标Y偏移
                    int nWidthDest,     // 目标宽度
                    int nHeightDest,    // 目标高度
                    HDC hdcSrc,         // 源DC
                    int nXOriginSrc,    // 源X起点
                    int nYOriginSrc,    // 源Y起点
                    COLORREF crTransparent  // 透明色,COLORREF类型
                    )
      if (nHeightSrc < 1) return false;

      HDC dc = CreateCompatibleDC(NULL);
      HBITMAP bitmap = CreateBitmap(nWidthSrc, nHeightSrc, 1, GetDeviceCaps(dc,
      BITSPIXEL), NULL);

         }

    
    HBITMAP oldBitmap = (HBITMAP)SelectObject(dc, bitmap);

     }

       
    HDC maskDC = CreateCompatibleDC(NULL);
     HBITMAP maskBitmap = CreateBitmap(nWidthSrc, nHeightSrc, 1, 1, NULL);

       }

       HBITMAP oldMask =  (HBITMAP)SelectObject(maskDC, maskBitmap);

       SetBkColor(maskDC, RGB(0,0,0));
       SetTextColor(maskDC, RGB(255,255,255));
       }

       SetBkColor(dc, crTransparent);
       BitBlt(maskDC, 0,0,nWidthSrc,nHeightSrc,dc,0,0,SRCINVERT);

      SetBkColor(dc, RGB(0,0,0));
       SetTextColor(dc, RGB(255,255,255));
       BitBlt(dc, 0,0,nWidthSrc,nHeightSrc,maskDC,0,0,SRCAND);

       HDC newMaskDC = CreateCompatibleDC(NULL);
       HBITMAP newMask;
       newMask = CreateBitmap(nWidthDest, nHeightDest, 1,
                                                  GetDeviceCaps(newMaskDC, BITSPIXEL), NULL);

       }

       SetStretchBltMode(newMaskDC, COLORONCOLOR);
       HBITMAP oldNewMask = (HBITMAP) SelectObject(newMaskDC, newMask);
       StretchBlt(newMaskDC, 0, 0, nWidthDest, nHeightDest, maskDC, 0, 0,
                    nWidthSrc, nHeightSrc, SRCCOPY);

       SelectObject(maskDC, oldMask);
       DeleteDC(maskDC);
       DeleteObject(maskBitmap);

       HDC newImageDC = CreateCompatibleDC(NULL);
       HBITMAP newImage = CreateBitmap(nWidthDest, nHeightDest, 1,
        GetDeviceCaps(newMaskDC, BITSPIXEL), NULL);

        }

       HBITMAP oldNewImage = (HBITMAP)SelectObject(newImageDC, newImage);
       StretchBlt(newImageDC, 0, 0, nWidthDest, nHeightDest, dc, 0, 0, nWidthSrc,
              nHeightSrc, SRCCOPY);

       SelectObject(dc, oldBitmap);
       DeleteDC(dc);
       DeleteObject(bitmap);    

       BitBlt( dcDest, nXOriginDest, nYOriginDest, nWidthDest, nHeightDest,
                          newMaskDC, 0, 0, SRCAND);

       BitBlt( dcDest, nXOriginDest, nYOriginDest, nWidthDest, nHeightDest,
                       newImageDC, 0, 0, SRCPAINT);

       SelectObject(newImageDC, oldNewImage);
       DeleteDC(newImageDC);
       SelectObject(newMaskDC, oldNewMask);
       DeleteDC(newMaskDC);
       DeleteObject(newImage);   
       DeleteObject(newMask);   

       return true;
}

 部分摘自：http://blog.csdn.net/xuweiqun/archive/2006/11/11/1378714.aspx，其中还补充了一些平时用到的方法