我正在使用:: TransparentBlt绘制一个标有Magenta RGB(255,0,255)的透明像素的bmp,但是:: TransparentBlt表现不正常,一些不透明的像素在结果中是透明的
我做错了什么?
原始图片:
来自:: TransparentBlt的结果
结果图像中的灰色区域是背景图像,原始bmp是:: TransparentBlt-ed
代码:
LRESULT jItems::paint ( )
{
HDC hdc ;
PAINTSTRUCT ps ;
RECT rect ;
::GetClientRect ( hwnd , &rect ) ;
hdc = ::BeginPaint ( hwnd , &ps ) ;
HDC dcSkin = ::CreateCompatibleDC ( hdc ); // memory dc for skin
HDC hMemDc = ::CreateCompatibleDC ( hdc ); // memory dc for painting
HBITMAP hmemBmp = ::CreateCompatibleBitmap ( hdc, rect.right - rect.left, rect.bottom - rect.top ); // Create bitmap to draw on
HBITMAP hOldMemBmp = ( HBITMAP ) ::SelectObject ( hMemDc, hmemBmp ); // select memory bitmap in memory dc
HBITMAP hOldSkinBmp = ( HBITMAP ) ::SelectObject ( dcSkin, this->hbitmap ); //select skin bitmap in skin memory dc
::FillRect ( hMemDc, &rect, ::CreateSolidBrush ( backgroundColor ) );
::BitBlt ( hMemDc, 0, 0, rect.right - rect.left,
rect.bottom - rect.top, dcSkin, 0, 0, SRCCOPY ); // Paint Skin on Memory DC
::SelectObject ( dcSkin, bottomEdge ); // select edge bitmap in skin memory dc
::TransparentBlt ( hMemDc, 0, 0, rect.right - rect.left,
rect.bottom - rect.top, dcSkin,
0, 0, 237, 10, RGB ( 255, 0, 255 ) ); // Paint edge on Memory DC
::BitBlt ( hdc, 0, 0, rect.right - rect.left,
rect.bottom - rect.top, hMemDc, 0, 0, SRCCOPY ); // Paint Skin on Window DC
//<<<... DeleteDC will leak memory if it holds a resource, so lets select the old bitmap back in the memory DCs
::SelectObject ( hMemDc, hOldMemBmp ); // select old bitmaps back to their respective DCs before deleting
::SelectObject ( dcSkin, hOldSkinBmp ); // select old bitmaps back to their respective DCs before deleting
::DeleteObject ( hOldSkinBmp );
::DeleteObject ( hOldMemBmp );
::DeleteObject( hmemBmp );
::DeleteDC ( hMemDc );
::DeleteDC ( dcSkin );
::EndPaint ( hwnd , &ps ) ;
return 0;
};
答案 0 :(得分:5)
来自TransparentBlt documentation。
如果源矩形和目标矩形的大小不同,则会拉伸源位图以匹配目标矩形。
在对TransparentBlt的调用中,目标矩形的大小(rect.right - rect.left,rect.bottom - rect.top)和源矩形的大小(237,10)。因此,位图被拉伸,您无法得到预期的结果。
我猜两种尺寸都应该是(237,10)。