请问，如何将一个在窗体中显示的BMP图（ico图标）显示为透明背景？

[batboy99]

请问，如何将一个在窗体中显示的BMP图（ico图标）显示为透明背景？以不挡住后面的内容。
谢谢回答，新手提问。

[mct1025]

透明位图的显示
http://www.vckbase.com/document/viewdoc.asp?id=532

[gzshd]

1 取出源位图各个象素点，将各像素点的RGB值乘以预设的透明度，放入一个暂存数组中。
2 取出背景图与源位图重叠部分的像素点，将各像素点的RGB值乘以100%-0%之间的预设的透明度，放入到另一个暂存数组中
3 将前两个步骤所产生的数组相加，就产生了所有半透明图的色彩值了。

BITMAP bm;
int x,y,s,t,m,i=0;
GetClientRect(&rect);
mdc = new CDC;
bitmap = new CBitmap;
bgbmp = new CBitmap;
mdc->CreateCompatibleDC(dc);
bgbmp->m_hObject = (HBITMAP)::LoadImage(NULL,"bground.bmp",IMAGE_BITMAP,rect.right,rect.bottom,LR_LOADFROMFILE);
bitmap->m_hObject = (HBITMAP)::LoadImage(NULL,"girl.bmp",IMAGE_BITMAP,298,329,LR_LOADFROMFILE);
bitmap->GetObject(sizeof(BITMAP),&bm);
unsigned char *px = new unsigned char[bm.bmHeight*bm.bmWidthBytes];
bitmap->GetBitmapBits(bm.bmHeight*bm.bmWidthBytes,px);
s = bm.bmHeight;
t = bm.bmWidth;
m = bm.bmWidthBytes;
for(y=0;y<bm.bmHeight;y++)
for(x=0;x<bm.bmWidth;x++)
{
px[x*3+y*bm.bmWidthBytes] *= 0.5;
px[x*3+1+y*bm.bmWidthBytes] *= 0.5;
px[x*3+2+y*bm.bmWidthBytes] *= 0.5;

}
bitmap->SetBitmapBits(bm.bmHeight*bm.bmWidthBytes,px);
bgbmp->GetObject(sizeof(BITMAP),&bm);
unsigned char *py = new unsigned char[bm.bmHeight*bm.bmWidthBytes];
bgbmp->GetBitmapBits(bm.bmHeight*bm.bmWidthBytes,py);
for(y=100;y<100+s;y++)
{
i = (y-100)*m;
for(x=100;x<100+t;x++)
{
py[x*3+y*bm.bmWidthBytes] = py[x*3+y*bm.bmWidthBytes]*0.5 + px[i];
py[x*3+1+y*bm.bmWidthBytes] = py[x*3+1+y*bm.bmWidthBytes]*0.5 + px[i+1];
py[x*3+2+y*bm.bmWidthBytes] = py[x*3+2+y*bm.bmWidthBytes]*0.5 + px[i+2];
i=i+3;
}
}
bgbmp->SetBitmapBits(bm.bmHeight*bm.bmWidthBytes,py);
mdc->SelectObject(bgbmp);
delete px;
delete py;

[lbird]

BOOL TransparentBlt(
int xDest,
int yDest,
int nDestWidth,
int nDestHeight,
CDC* pSrcDC,
int xSrc,
int ySrc,
int nSrcWidth,
int nSrcHeight,
UINT clrTransparent ／／透明的颜色
);

[kangfx]

gz

[wguaner]

学习ING，帮顶。

[wangzi163]

up

[kongyunzhongque]

up