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
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
void
CCommon::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
)
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...
...
{
HBITMAP hOldImageBMP, hImageBMP = CreateCompatibleBitmap(hdcDest, nWidthDest, nHeightDest); // 创建兼容位图
HBITMAP hOldMaskBMP, hMaskBMP = CreateBitmap(nWidthDest, nHeightDest, 1, 1, NULL); // 创建单色掩码位图
HDC hImageDC = CreateCompatibleDC(hdcDest);//临时DC
HDC hMaskDC = CreateCompatibleDC(hdcDest);//临时掩码DC
hOldImageBMP = (HBITMAP)SelectObject(hImageDC, hImageBMP);
hOldMaskBMP = (HBITMAP)SelectObject(hMaskDC, hMaskBMP);
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// 将源DC中的位图拷贝到临时DC中,源DC已经载入位图
BitBlt(hImageDC, 0, 0, nWidthDest, nHeightDest, hdcSrc, nXOriginSrc, nYOriginSrc, SRCCOPY);
// 设置临时DC的透明色
SetBkColor(hImageDC, crTransparent);
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// 生成透明区域为白色,其它区域为黑色的临时掩码DC的掩码位图
// 位图来自临时DC
BitBlt(hMaskDC, 0, 0, nWidthDest, nHeightDest, hImageDC, 0, 0, SRCCOPY);
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// 生成透明区域为黑色,其它区域保持不变的位图
SetBkColor(hImageDC, RGB(0,0,0));
SetTextColor(hImageDC, RGB(255,255,255));
BitBlt(hImageDC, 0, 0, nWidthDest, nHeightDest, hMaskDC, 0, 0, SRCAND);
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// 透明部分保持屏幕不变,其它部分变成黑色
SetBkColor(hdcDest,RGB(255,255,255));
SetTextColor(hdcDest,RGB(0,0,0));
BitBlt(hdcDest, nXOriginDest, nYOriginDest, nWidthDest, nHeightDest, hMaskDC, 0, 0, SRCAND);
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// "或"运算,生成最终效果
BitBlt(hdcDest, nXOriginDest, nYOriginDest, nWidthDest, nHeightDest, hImageDC, 0, 0, SRCPAINT);
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// 清理、恢复
SelectObject(hImageDC, hOldImageBMP);
DeleteDC(hImageDC);
SelectObject(hMaskDC, hOldMaskBMP);
DeleteDC(hMaskDC);
DeleteObject(hImageBMP);
DeleteObject(hMaskBMP);
}
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//
用于没有掩码图,只有指定透明色,可以进行伸缩
void
CCommon::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
)

...
...
{
HBITMAP hOldImageBMP, hImageBMP = CreateCompatibleBitmap(hdcDest, nWidthDest, nHeightDest); // 创建兼容位图
HBITMAP hOldMaskBMP, hMaskBMP = CreateBitmap(nWidthDest, nHeightDest, 1, 1, NULL); // 创建单色掩码位图
HDC hImageDC = CreateCompatibleDC(hdcDest);
HDC hMaskDC = CreateCompatibleDC(hdcDest);
hOldImageBMP = (HBITMAP)SelectObject(hImageDC, hImageBMP);
hOldMaskBMP = (HBITMAP)SelectObject(hMaskDC, hMaskBMP);
// 将源DC中的位图拷贝到临时DC中
if (nWidthDest == nWidthSrc && nHeightDest == nHeightSrc)
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......{
BitBlt(hImageDC, 0, 0, nWidthDest, nHeightDest, hdcSrc, nXOriginSrc, nYOriginSrc, SRCCOPY);
}
else
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......{
StretchBlt(hImageDC, 0, 0, nWidthDest, nHeightDest,
hdcSrc, nXOriginSrc, nYOriginSrc, nWidthSrc, nHeightSrc, SRCCOPY);
}
// 设置透明色
SetBkColor(hImageDC, crTransparent);
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// 生成透明区域为白色,其它区域为黑色的掩码位图
BitBlt(hMaskDC, 0, 0, nWidthDest, nHeightDest, hImageDC, 0, 0, SRCCOPY);
// 生成透明区域为黑色,其它区域保持不变的位图
SetBkColor(hImageDC, RGB(0,0,0));
SetTextColor(hImageDC, RGB(255,255,255));
BitBlt(hImageDC, 0, 0, nWidthDest, nHeightDest, hMaskDC, 0, 0, SRCAND);
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// 透明部分保持屏幕不变,其它部分变成黑色
SetBkColor(hdcDest,RGB(0xff,0xff,0xff));
SetTextColor(hdcDest,RGB(0,0,0));
BitBlt(hdcDest, nXOriginDest, nYOriginDest, nWidthDest, nHeightDest, hMaskDC, 0, 0, SRCAND);
// "或"运算,生成最终效果
BitBlt(hdcDest, nXOriginDest, nYOriginDest, nWidthDest, nHeightDest, hImageDC, 0, 0, SRCPAINT);
SelectObject(hImageDC, hOldImageBMP);
DeleteDC(hImageDC);
SelectObject(hMaskDC, hOldMaskBMP);
DeleteDC(hMaskDC);
DeleteObject(hImageBMP);
DeleteObject(hMaskBMP);
}
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指定掩码图,和掩码图属于不同图片
void
CCommon::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,
int
nXOriginSrc,
//
源X起点
int
nYOriginSrc,
//
源Y起点
COLORREF crTransparent
//
透明色,COLORREF类型
)

...
...
{
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HBITMAP hOldImageBMP, hImageBMP = CreateCompatibleBitmap(hdcDest, nWidthDest, nHeightDest); // 创建兼容位图
HDC hImageDC = CreateCompatibleDC(hdcDest);//临时DC
hOldImageBMP = (HBITMAP)SelectObject(hImageDC, hImageBMP);
// 将源DC中的位图拷贝到临时DC中,源DC已经载入位图
BitBlt(hImageDC, 0, 0, nWidthDest, nHeightDest, hdcSrc, nXOriginSrc, nYOriginSrc, SRCCOPY);
// 设置临时DC的透明色
SetBkColor(hImageDC, crTransparent);
// 生成透明区域为黑色,其它区域保持不变的位图
SetBkColor(hImageDC, RGB(0,0,0));
SetTextColor(hImageDC, RGB(255,255,255));
BitBlt(hImageDC, 0, 0, nWidthDest, nHeightDest, hdcMask, 0, 0, SRCAND);
// 透明部分保持屏幕不变,其它部分变成黑色
SetBkColor(hdcDest,RGB(255,255,255));
SetTextColor(hdcDest,RGB(0,0,0));
BitBlt(hdcDest, nXOriginDest, nYOriginDest, nWidthDest, nHeightDest, hdcMask, 0, 0, SRCAND);
// "或"运算,生成最终效果
BitBlt(hdcDest, nXOriginDest, nYOriginDest, nWidthDest, nHeightDest, hImageDC, 0, 0, SRCPAINT);
// 清理、恢复
SelectObject(hImageDC, hOldImageBMP);
DeleteDC(hImageDC);
DeleteObject(hImageBMP);
}
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
指定图片和掩码图同属于一张图片
void
CCommon::DrawTransBitmap(HDC hDC,
int
nPosX,
int
nPosY,
int
nCX,
int
nCY, HBITMAP hObj)
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...
...
{
HDC hMemDC= CreateCompatibleDC(hDC);
HBITMAP hOldBMP=(HBITMAP)::SelectObject(hMemDC,hObj);
BitBlt(hDC,nPosX,nPosY,nCX,nCY, hMemDC,nCX,0,SRCAND);
BitBlt(hDC,nPosX,nPosY,nCX,nCY, hMemDC,0,0,SRCPAINT);
SelectObject(hMemDC,hOldBMP);
DeleteDC(hMemDC);
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}
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HRGN CCommon::CreateBitmapRgn(
int
nWidth,
int
nHeight,HBITMAP hbmp, COLORREF TransColor)
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...
...
{

HDC hmemDC;
//创建与传入DC兼容的临时DC
hmemDC = ::CreateCompatibleDC(NULL);
HBITMAP hOldBmp = (HBITMAP)::SelectObject(hmemDC,hbmp);
//创建总的窗体区域,初始region为0
HRGN hrgn;
hrgn = ::CreateRectRgn(0,0,0,0);
int y;
for(y=0;y<nHeight ;y++)
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......{
HRGN rgnTemp; //保存临时region
int iX = 0;
do
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......{
//跳过透明色找到下一个非透明色的点.
while (iX < nWidth && ::GetPixel(hmemDC,iX, y) == TransColor)
iX++;
//记住这个起始点
int iLeftX = iX;
//寻找下个透明色的点
while (iX < nWidth && ::GetPixel(hmemDC,iX, y) != TransColor)
++iX;
//创建一个包含起点与重点间高为1像素的临时“region”
rgnTemp=::CreateRectRgn(iLeftX, y, iX, y+1);
//合并到主"region".
CombineRgn( hrgn,hrgn,rgnTemp, RGN_OR);
//删除临时"region",否则下次创建时和出错
::DeleteObject(rgnTemp);
}while(iX <nWidth );
iX = 0;
}
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::SelectObject(hmemDC,hOldBmp);
::DeleteDC(hmemDC);
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return hrgn;
}