求助！！用c++ 获取当前屏幕的图像

[nwnw5921]

求助！求助！SOS! 我想用c++实现获取当前的屏幕图像，并且显示出来！ 怎么写啊,没有一点头绪，请高手、大侠们指点指点小弟啊~ 在此先谢过了！！

[碎炎]

这个要调api的吧

[科技完美生活]

你是什么系统啊，不同系统方法不一样啊

[alweeq86]

HWND currentHwnd=::FindWindow(NULL,L"Microsoft Visual Studio");
HDC currentDc=::GetDC(currentHwnd);
HDC dialogDc=::GetWindowDC(m_hWnd);
::BitBlt(dialogDc,0,0,200,200,currentDc,0,0,SRCCOPY);

[afreet2006]

7楼能够实现， 不过保存路径得事先创建好

[nwnw5921]

用MFC啊~ 俺是新手，还有什么系统啊？ 3楼的函数，我先试试去~ 都谢谢了啊~

[lt114896]

HBITMAP CopyScreenToBitmap(int &nWidth, int &nHeight)
{
	//屏幕和内存设备描述表
	HDC hScrDC, hMemDC;
	//位图句柄
	HBITMAP hBitmap,hOldBitmap;
	//屏幕分辨率
	int xScrn,yScrn;
	//为屏幕创建设备描述表
	hScrDC = CreateDC("DISPLAY", NULL, NULL, NULL);
	//为屏幕设备描述表创建兼容的内存设备描述表
	hMemDC = CreateCompatibleDC(hScrDC);
	//获得屏幕分辨率
	xScrn = GetDeviceCaps(hScrDC, HORZRES);
	yScrn = GetDeviceCaps(hScrDC, VERTRES);
	
	//存储屏幕的宽度
	nWidth = xScrn;
	nHeight = yScrn;
	
	//创建一个与屏幕设备描述表兼容的 位图
	hBitmap = CreateCompatibleBitmap(hScrDC, xScrn,yScrn);
	//把新位图选到内存设备描述表中
	hOldBitmap = (HBITMAP)SelectObject(hMemDC, hBitmap);
	//把屏幕设备描述表拷贝到内存设备描述表中
	BitBlt(hMemDC, 0, 0, xScrn, yScrn, hScrDC, 0, 0, SRCCOPY);
	//得到屏幕位图句柄
	hBitmap = (HBITMAP)SelectObject(hMemDC, hOldBitmap);
	//清除
	DeleteDC(hScrDC);
	DeleteDC(hMemDC);
	
	//返回位图句柄
	return hBitmap;
}
void CJiepingDlg::OnButDisp() 
{
	// TODO: Add your control notification handler code here
	HBITMAP bmp;
	int nWidth,nHeight;
	//zhuapingg
	bmp = CopyScreenToBitmap(nWidth, nHeight);
	//将抓取的屏幕压缩先是到窗体上
	CDC *pDC = new CClientDC(this);
	CDC srcDC;
	CRect rect;
	this->GetClientRect(&rect);
	//	GetClientRect(&rect);
	rect.DeflateRect(0,20);
	//绘制显示区域矩形
	CPen pen;
	pen.CreatePen(PS_SOLID, 2, RGB(0,255,255));
	pDC->SelectObject(&pen);
	pDC->Rectangle(rect);
	//、显示屏幕
	srcDC.CreateCompatibleDC(pDC);
	srcDC.SelectObject(bmp);
	
	//压缩显示抓取的位图
	pDC->StretchBlt(rect.left+2,rect.top+2,rect.right-rect.left-4,rect.bottom-rect.top-4,&srcDC,0,0,nWidth,nHeight,SRCCOPY);
	pen.DeleteObject();
	DeleteObject(bmp);
	srcDC.DeleteDC();
	delete pDC;
}

[pathuang68]

办法有很多，你还可以用DirectX截取屏幕上的视频 + 音频。

[GARY]

楼主是要截屏吧。
如果是windows系统，就是“绘图”的反过程
将HDC保存为图像文件(如bmp)

// 获取HDC的数据
BOOL GetHDCData(HDC hdc,const RECT &rcDC,std::vector<BYTE> &vtBuf)
{
	BOOL bRes = FALSE;		
	HBITMAP hBmp = NULL;
	HDC hdcMem = NULL;

	__try
	{
		//Initilaize the bitmap information	
		BITMAPINFO bmpInfo = {0};
		bmpInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
		bmpInfo.bmiHeader.biWidth = rcDC.right - rcDC.left;
		bmpInfo.bmiHeader.biHeight = rcDC.bottom - rcDC.top;
		bmpInfo.bmiHeader.biPlanes = 1;
		bmpInfo.bmiHeader.biBitCount = 24;

		//Create the compatible DC to get the data
		hdcMem = CreateCompatibleDC(hdc);
		if(hdcMem == NULL)
		{
			//ASSERT(FALSE);
			//RETAILMSG(TRUE,(TEXT("CreateCompatibleDC failed! Error Code:0x%x\r\n"),GetLastError()));
			__leave;
		}

		//Get the data from the memory DC	
		BYTE *pData = NULL;
		hBmp = CreateDIBSection(hdcMem,&bmpInfo,DIB_RGB_COLORS,reinterpret_cast<VOID **>(&pData),NULL,0);
		if(hBmp == NULL)
		{
			//ASSERT(FALSE);
			//RETAILMSG(TRUE,(TEXT("CreateDIBSection failed! Error Code:0x%x\r\n"),GetLastError()));
			__leave;
		}
		HGDIOBJ hOldObj = SelectObject(hdcMem, hBmp);
		
		//Draw to the memory DC
		SIZE sizeImg = {bmpInfo.bmiHeader.biWidth,bmpInfo.bmiHeader.biHeight};
		SIZE sizeDC = {rcDC.right - rcDC.left,rcDC.bottom - rcDC.top};
		StretchBlt(hdcMem,
					0,
					0,
					sizeImg.cx,
					sizeImg.cy,
					hdc,
					rcDC.left,
					rcDC.top,
					sizeDC.cx,
					sizeDC.cy,
					SRCCOPY);
		

		vtBuf.resize(sizeImg.cx * sizeImg.cy * 3);
		memcpy(&vtBuf[0],pData,vtBuf.size());
	
		SelectObject(hdcMem, hOldObj);

		bRes = TRUE;
	
	}
	__finally
	{

		if(hBmp != NULL)
		{
			DeleteObject(hBmp);
		}

		if(hdcMem != NULL)
		{
			DeleteDC(hdcMem);
		}
	}

	return bRes;
}

// 保存HDC为BMP文件
BOOL WriteBmp(const TSTRING &strFile,HDC hdc,const RECT &rcDC)
{
	std::vector<BYTE> vtData;
	if(GetHDCData(hdc,rcDC,vtData) == FALSE)
	{
		return FALSE;
	}
	
	SIZE sizeImg = {rcDC.right - rcDC.left,rcDC.bottom - rcDC.top};

	BITMAPINFOHEADER bmInfoHeader = {0};
	bmInfoHeader.biSize = sizeof(BITMAPINFOHEADER);
	bmInfoHeader.biWidth = sizeImg.cx;
	bmInfoHeader.biHeight = sizeImg.cy;
	bmInfoHeader.biPlanes = 1;
	bmInfoHeader.biBitCount = 24;

	//Bimap file header in order to write bmp file
	BITMAPFILEHEADER bmFileHeader = {0};
	bmFileHeader.bfType = 0x4d42;  //bmp  
	bmFileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
	bmFileHeader.bfSize = bmFileHeader.bfOffBits + ((bmInfoHeader.biWidth * bmInfoHeader.biHeight) * 3); ///3=(24 / 8)

	HANDLE hFile = CreateFile(strFile.c_str(),GENERIC_WRITE,0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
	if(hFile == INVALID_HANDLE_VALUE)
	{
		return FALSE;
	}

	DWORD dwWrite = 0;
	WriteFile(hFile,&bmFileHeader,sizeof(BITMAPFILEHEADER),&dwWrite,NULL);
	WriteFile(hFile,&bmInfoHeader, sizeof(BITMAPINFOHEADER),&dwWrite,NULL);
	WriteFile(hFile,&vtData[0], vtData.size(),&dwWrite,NULL);


	CloseHandle(hFile);

	return TRUE;
}

// 截屏
HDC hdc = CreateDC(_T("DISPLAY"), NULL, NULL, NULL);
RECT rcSave = {0,0,GetDeviceCaps(hdc,HORZRES),GetDeviceCaps(hdc,VERTRES)};
WriteBmp(TEXT("D:\\Temp\\ScreenCapture.BMP"),hdc,rcSave);
DeleteDC(hdc);

[koolxiaoyuer]

Mark下，有时间研究下 L5 & L7

[就想叫yoko]

MFC QT都行
CSDN下载频道都有

[老猿的春天]

给你个思路，自己做，抓屏程序，先把屏幕DC拷贝到内存，这个内存，你可以用来保存为图片文件，你也可以把内存绘制到屏幕

[wskuge]

MFC包装的东西太多了，感觉用起来好累赘。

[灼眼的超哥]

[Quote=引用 6 楼 pathuang68 的回复:]

办法有很多，你还可以用DirectX截取屏幕上的视频 + 音频。
[/Quote]
屏幕上有音频？