屏幕截图保存PNG图像 [英] screenshot saving PNG image

问题描述

大家好，

我想捕获屏幕并将其保存为PNG.

我有代码捕获屏幕，但是它保存到BMP:(...

Hi all,

I want to capture screen and SAVE it to PNG.

I had code capture screen, but it save to BMP :(...

inline int GetFilePointer(HANDLE FileHandle){
	return SetFilePointer(FileHandle, 0, 0, FILE_CURRENT);
}
bool SaveBMPFile(char *filename, HBITMAP bitmap, HDC bitmapDC, int width, int height){
	bool Success=0;
	HDC SurfDC=NULL;
	HBITMAP OffscrBmp=NULL;
	HDC OffscrDC=NULL;
	LPBITMAPINFO lpbi=NULL;
	LPVOID lpvBits=NULL;
	HANDLE BmpFile=INVALID_HANDLE_VALUE;
	BITMAPFILEHEADER bmfh;
	if ((OffscrBmp = CreateCompatibleBitmap(bitmapDC, width, height)) == NULL)
		return 0;
	if ((OffscrDC = CreateCompatibleDC(bitmapDC)) == NULL)
		return 0;
	HBITMAP OldBmp = (HBITMAP)SelectObject(OffscrDC, OffscrBmp);
	BitBlt(OffscrDC, 0, 0, width, height, bitmapDC, 0, 0, SRCCOPY);
	if ((lpbi = (LPBITMAPINFO)(new char[sizeof(BITMAPINFOHEADER) + 256 * sizeof(RGBQUAD)])) == NULL)
		return 0;
	ZeroMemory(&lpbi->bmiHeader, sizeof(BITMAPINFOHEADER));
	lpbi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
	SelectObject(OffscrDC, OldBmp);
	if (!GetDIBits(OffscrDC, OffscrBmp, 0, height, NULL, lpbi, DIB_RGB_COLORS))
		return 0;
	if ((lpvBits = new char[lpbi->bmiHeader.biSizeImage]) == NULL)
		return 0;
	if (!GetDIBits(OffscrDC, OffscrBmp, 0, height, lpvBits, lpbi, DIB_RGB_COLORS))
		return 0;
	if ((BmpFile = CreateFile(filename,
						GENERIC_WRITE,
						0, NULL,
						CREATE_ALWAYS,
						FILE_ATTRIBUTE_NORMAL,
						NULL)) == INVALID_HANDLE_VALUE)
		return 0;
	DWORD Written;
	bmfh.bfType = 19778;
	bmfh.bfReserved1 = bmfh.bfReserved2 = 0;
	if (!WriteFile(BmpFile, &bmfh, sizeof(bmfh), &Written, NULL))
		return 0;
	if (Written < sizeof(bmfh))
		return 0;
	if (!WriteFile(BmpFile, &lpbi->bmiHeader, sizeof(BITMAPINFOHEADER), &Written, NULL))
		return 0;
	if (Written < sizeof(BITMAPINFOHEADER))
		return 0;
	int PalEntries;
	if (lpbi->bmiHeader.biCompression == BI_BITFIELDS)
		PalEntries = 3;
	else PalEntries = (lpbi->bmiHeader.biBitCount <= 8) ?
					  (int)(1 << lpbi->bmiHeader.biBitCount) : 0;
	if(lpbi->bmiHeader.biClrUsed)
	PalEntries = lpbi->bmiHeader.biClrUsed;
	if(PalEntries){
	if (!WriteFile(BmpFile, &lpbi->bmiColors, PalEntries * sizeof(RGBQUAD), &Written, NULL))
		return 0;
		if (Written < PalEntries * sizeof(RGBQUAD))
			return 0;
	}
	bmfh.bfOffBits = GetFilePointer(BmpFile);
	if (!WriteFile(BmpFile, lpvBits, lpbi->bmiHeader.biSizeImage, &Written, NULL))
		return 0;
	if (Written < lpbi->bmiHeader.biSizeImage)
		return 0;
	bmfh.bfSize = GetFilePointer(BmpFile);
	SetFilePointer(BmpFile, 0, 0, FILE_BEGIN);
	if (!WriteFile(BmpFile, &bmfh, sizeof(bmfh), &Written, NULL))
		return 0;
	if (Written < sizeof(bmfh))
		return 0;
	return 1;
}
bool ScreenCapture(int x, int y, int width, int height, char *filename){
	HDC hDc = CreateCompatibleDC(0);
	HBITMAP hBmp = CreateCompatibleBitmap(GetDC(0), width, height);
	SelectObject(hDc, hBmp);
	BitBlt(hDc, 0, 0, width, height, GetDC(0), x, y, SRCCOPY);
	bool ret = SaveBMPFile(filename, hBmp, hDc, width, height);
	DeleteObject(hBmp);
	return ret;
}

我可以编辑此代码以保存PNG吗?

非常感谢.

Can i edit this code to save PNG ?

Thank very much.

推荐答案

此CodeProject文章可以在这里为您提供帮助:
CxImage [ ^ ].

—SA

This CodeProject article can help you here:
CxImage[^].

—SA

How do you load a PNG image in C++?[^] should be quite useful.

我一直都走了与 PNGLIB [ ^ ]在我的所有应用程序中总能正常运行.

I have always gone with PNGLIB[^] which did always fine in all of my applications.

这篇关于屏幕截图保存PNG图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！