按钮剪裁函数//不明白什么情况下会出空间不足的情况if ( pRgnData->nCount >= cBlocks * MAXBUF ){

[mirroatl196]

HRGN GdixConButton::CreateRgnFromBitmap(HBITMAP hBmp, COLORREF color)
{
	if (!hBmp) return NULL;

	BITMAP bm;
	GetObject( hBmp, sizeof(BITMAP), &bm );	// get bitmap attributes

	CDC dcBmp;
	CDC *pDC = GetDC();
	if (!pDC) return NULL;
	dcBmp.CreateCompatibleDC(pDC);	//Creates a memory device context for the bitmap
	ReleaseDC(pDC);
	HBITMAP hOldBitmap = (HBITMAP)dcBmp.SelectObject(hBmp);	//selects the bitmap in the device context

	const DWORD RDHDR = sizeof(RGNDATAHEADER);
	const DWORD MAXBUF = 40;		// size of one block in RECTs
									// (i.e. MAXBUF*sizeof(RECT) in bytes)
	LPRECT	pRects;								
	DWORD	cBlocks = 0;			// number of allocated blocks

	INT		i, j;					// current position in mask image
	INT		first = 0;				// left position of current scan line
									// where mask was found
	bool	wasfirst = false;		// set when if mask was found in current scan line
	bool	ismask;					// set when current color is mask color

	// allocate memory for region data
	RGNDATAHEADER* pRgnData = (RGNDATAHEADER*)new BYTE[ RDHDR + ++cBlocks * MAXBUF * sizeof(RECT) ];
	memset( pRgnData, 0, RDHDR + cBlocks * MAXBUF * sizeof(RECT) );
	// fill it by default
	pRgnData->dwSize	= RDHDR;
	pRgnData->iType		= RDH_RECTANGLES;
	pRgnData->nCount	= 0;
	for ( i = 0; i < bm.bmHeight; i++ )
	for ( j = 0; j < bm.bmWidth; j++ ){
		// get color
		ismask=(dcBmp.GetPixel(j,bm.bmHeight-i-1)!=color);
		// place part of scan line as RECT region if transparent color found after mask color or
		// mask color found at the end of mask image
		if (wasfirst && ((ismask && (j==(bm.bmWidth-1)))||(ismask ^ (j<bm.bmWidth)))){
			// get offset to RECT array if RGNDATA buffer
			pRects = (LPRECT)((LPBYTE)pRgnData + RDHDR);
			// save current RECT
			pRects[ pRgnData->nCount++ ] = CRect( first, bm.bmHeight - i - 1, j+(j==(bm.bmWidth-1)), bm.bmHeight - i );
			// if buffer full reallocate it
			if ( pRgnData->nCount >= cBlocks * MAXBUF ){
				LPBYTE pRgnDataNew = new BYTE[ RDHDR + ++cBlocks * MAXBUF * sizeof(RECT) ];
				memcpy( pRgnDataNew, pRgnData, RDHDR + (cBlocks - 1) * MAXBUF * sizeof(RECT) );
				delete pRgnData;
				pRgnData = (RGNDATAHEADER*)pRgnDataNew;
			}
			wasfirst = false;
		} else if ( !wasfirst && ismask ){		// set wasfirst when mask is found
			first = j;
			wasfirst = true;
		}
	}
	dcBmp.SelectObject( hOldBitmap );
	dcBmp.DeleteDC();	//release the bitmap

	HRGN hRgn=CreateRectRgn(0, 0, 0, 0);
	ASSERT( hRgn!=NULL );
	pRects = (LPRECT)((LPBYTE)pRgnData + RDHDR);
	for(i=0;i<(int)pRgnData->nCount;i++)
	{
		HRGN hr=CreateRectRgn(pRects[i].left, pRects[i].top, pRects[i].right, pRects[i].bottom);
		VERIFY(CombineRgn(hRgn, hRgn, hr, RGN_OR)!=ERROR);
		if (hr) DeleteObject(hr);
	}
	ASSERT( hRgn!=NULL );
	delete pRgnData;
	return hRgn;
}

[allenhiman]

代码好长 帮顶吧

[jimette]

// if buffer full reallocate it if ( pRgnData->nCount >= cBlocks * MAXBUF ){ LPBYTE pRgnDataNew = new BYTE[ RDHDR + ++cBlocks * MAXBUF * sizeof(RECT) ]; memcpy( pRgnDataNew, pRgnData, RDHDR + (cBlocks - 1) * MAXBUF * sizeof(RECT) ); delete pRgnData; pRgnData = (RGNDATAHEADER*)pRgnDataNew; } wasfirst = false; } else if ( !wasfirst && ismask ){ // set wasfirst when mask is found first = j; wasfirst = true; } 代码是你自己写的 具体做什么你应该最清楚 RGNDATAHEADER* pRgnData = (RGNDATAHEADER*)new BYTE[ RDHDR + ++cBlocks * MAXBUF * sizeof(RECT) ]; 这里是第一次申请空间 然后在循环里 pRects[ pRgnData->nCount++ ] = CRect( first, bm.bmHeight - i - 1, j+(j==(bm.bmWidth-1)), bm.bmHeight - i ); pRgnData->nCount一直在累加 所以要判断之前的空间是否够用 不够就重新分配 至于为什么这么做还是要问你自己啊 http://bbs.csdn.net/topics/390332312 提过了一次！

[mirro187_]

cBlocks * MAXBUF是什么意思??? 大哥 别复制粘贴 网上的 我看过

引用 2 楼 sha_jinhao 的回复:

// if buffer full reallocate it if ( pRgnData->nCount >= cBlocks * MAXBUF ){ LPBYTE pRgnDataNew = new BYTE[ RDHDR + ++cBlocks * MAXBUF * sizeof(RECT) ]; ……