怎样用API写位图文件

[wsdhren]

我可以用API的LoadImage函数读取.bmp的图片文件并提取其像素数组进行处理
但是处理好之后我怎样.bmp的文件啊？
处理好的图像我存在HBITMAP类型的变量中。
求大侠指导！

[maoxing63570]

void ScreenCapture(int bitCount,bool isDrawCursor)
{
	int	color_num = bitCount <= 8 ? 1 << bitCount : 0;
	int nBISize = sizeof(BITMAPINFOHEADER) + (color_num * sizeof(RGBQUAD));
	BITMAPINFO	*lpbmi = (BITMAPINFO *) new BYTE[nBISize];
	int nWidth=GetSystemMetrics(SM_CXSCREEN);
	int nHeight=GetSystemMetrics(SM_CYSCREEN);
	BITMAPINFOHEADER	*lpbmih = &(lpbmi->bmiHeader);
	lpbmih->biSize = sizeof(BITMAPINFOHEADER);
	lpbmih->biWidth = nWidth;
	lpbmih->biHeight = nHeight;
	lpbmih->biPlanes = 1;
	lpbmih->biBitCount = bitCount;
	lpbmih->biCompression = BI_RGB;
	lpbmih->biXPelsPerMeter = 0;
	lpbmih->biYPelsPerMeter = 0;
	lpbmih->biClrUsed = 0;
	lpbmih->biClrImportant = 0;
	lpbmih->biSizeImage = (((lpbmih->biWidth * lpbmih->biBitCount + 31) & ~31) >> 3) * lpbmih->biHeight;

	HDC	hDC = GetDC(NULL);
	HDC hMemDC=CreateCompatibleDC(hDC);
	HBITMAP hBmp = CreateCompatibleBitmap(hMemDC, 1, 1); // 高宽不能为0

	GetDIBits(hMemDC, hBmp, 0, 0, NULL, lpbmi, DIB_RGB_COLORS);
	LPBYTE m_lpvFullBits=NULL;
	HPALETTE hPal = (HPALETTE)GetStockObject(DEFAULT_PALETTE ); //得到系统默认调色板
	hPal = SelectPalette(hMemDC,hPal,FALSE);
	HBITMAP lpbitmap=CreateDIBSection(hMemDC, lpbmi, DIB_RGB_COLORS, (void**)&m_lpvFullBits, NULL, NULL);
	HGDIOBJ hOldObject=SelectObject(hMemDC,(HGDIOBJ)lpbitmap);
	BitBlt(hMemDC,0,0,nWidth,nHeight,hDC,0,0,SRCCOPY);

	if(isDrawCursor)
	{
		POINT pt;
		ICONINFO iconinfo;
		GetCursorPos(&pt);
		HCURSOR hIcon=GetCursor();
		if(GetIconInfo(hIcon,&iconinfo))
		{
			pt.x-=iconinfo.xHotspot;
			pt.y-=iconinfo.yHotspot;
			if(iconinfo.hbmColor!=NULL)
				DeleteObject(iconinfo.hbmColor);

			if(iconinfo.hbmMask!=NULL)
				DeleteObject(iconinfo.hbmMask);
		}
		DrawIconEx(hMemDC,pt.x,pt.y,hIcon,0,0,0,NULL,DI_NORMAL | DI_COMPAT);
	}

	BITMAPFILEHEADER bh;
	ZeroMemory(&bh,sizeof(bh));
	bh.bfOffBits=sizeof(BITMAPFILEHEADER)+nBISize;
	bh.bfSize=bh.bfOffBits+lpbmih->biSizeImage;
	bh.bfType=0x4d42;
	HANDLE hFile=INVALID_HANDLE_VALUE;
	__try
	{
		HANDLE hFile=CreateFile(L"Desktop.bmp",GENERIC_READ | GENERIC_WRITE,
			FILE_SHARE_READ | FILE_SHARE_WRITE,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);

		DWORD dwBytesWritten=0;
		if(!WriteFile(hFile,&bh,sizeof(bh),&dwBytesWritten,NULL))
			__leave;

		if(!WriteFile(hFile,lpbmi,nBISize,&dwBytesWritten,NULL))
			__leave;

		if(!WriteFile(hFile,m_lpvFullBits,lpbmi->bmiHeader.biSizeImage,&dwBytesWritten,NULL))
			__leave;
	}
	__finally
	{
		if(hFile!=INVALID_HANDLE_VALUE)
			CloseHandle(hFile);

		SelectObject(hMemDC,hOldObject);
		DeleteDC(hMemDC);
		ReleaseDC(NULL,hDC);
		DeleteObject(lpbitmap);
		DeleteObject(hBmp);
		delete [] lpbmi;
	}

}

给你个例子

[「已注销」]

1楼高手，我是来膜拜的

[yuucyf]

了解Bitmap图像格式后，跟写普通的文件没有什么区别.
如果楼主想真正弄懂，那必须要学习学习Bitmap图像格式，其实也挺简单的.