// vc截图.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#include <afxwin.h> //#include <Windows.h>HBITMAP CopyScreenToBitmap(LPRECT lpRect) //lpRect 代表选定区域{ HDC hScrDC, hMemDC; // 屏幕和内存设备描述表 HBITMAP hBitmap,hOldBitmap; // 位图句柄 int nX, nY, nX2, nY2; // 选定区域坐标 int nWidth, nHeight; // 位图宽度和高度 int xScrn, yScrn; // 屏幕分辨率 // 确保选定区域不为空矩形 if (IsRectEmpty(lpRect)) return NULL; //为屏幕创建设备描述表 hScrDC = CreateDCA("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); // 获得选定区域坐标 nX = lpRect->left; nY = lpRect->top; nX2 = lpRect->right; nY2 = lpRect->bottom; // 获得屏幕分辨率 xScrn = GetDeviceCaps(hScrDC, HORZRES); yScrn = GetDeviceCaps(hScrDC, VERTRES); //确保选定区域是可见的 if (nX < 0) nX = 0; if (nY < 0) nY = 0; if (nX2 > xScrn) nX2 = xScrn; if (nY2 > yScrn) nY2 = yScrn; nWidth = nX2 - nX; nHeight = nY2 - nY; // 创建一个与屏幕设备描述表兼容的位图 hBitmap=CreateCompatibleBitmap(hScrDC,nWidth,nHeight); // 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, nWidth,nHeight,hScrDC, nX, nY, SRCCOPY); //得到屏幕位图的句柄 hBitmap=(HBITMAP)SelectObject(hMemDC,hOldBitmap); //清除 DeleteDC(hScrDC); DeleteDC(hMemDC); // 返回位图句柄 return hBitmap;} int SaveBitmapToFile(HBITMAP hBitmap, LPSTR lpFileName) //hBitmap 为刚才的屏幕位图句柄{ //lpFileName 为位图文件名 HDC hDC; //设备描述表 int iBits; //当前显示分辨率下每个像素所占字节数 WORD wBitCount; //位图中每个像素所占字节数 //定义调色板大小， 位图中像素字节大小 ， 位图文件大小 ， 写入文件字节数 DWORD dwPaletteSize=0,dwBmBitsSize,dwDIBSize, dwWritten; BITMAP Bitmap; //位图属性结构 BITMAPFILEHEADER bmfHdr; //位图文件头结构 BITMAPINFOHEADER bi; //位图信息头结构 LPBITMAPINFOHEADER lpbi; //指向位图信息头结构 HANDLE fh, hDib, hPal; HPALETTE hOldPal=NULL; //定义文件，分配内存句柄，调色板句柄 //计算位图文件每个像素所占字节数 hDC = CreateDCA("DISPLAY",NULL,NULL,NULL); iBits = GetDeviceCaps(hDC, BITSPIXEL) * GetDeviceCaps(hDC, PLANES); DeleteDC(hDC); if (iBits <= 1) wBitCount = 1; else if (iBits <= 4) wBitCount = 4; else if (iBits <= 8) wBitCount = 8; else if (iBits <= 24) wBitCount = 24;else wBitCount = 32; //计算调色板大小 if (wBitCount <= 8) dwPaletteSize=(1<<wBitCount)*sizeof(RGBQUAD); //设置位图信息头结构 GetObject(hBitmap, sizeof(BITMAP), (LPSTR)&Bitmap); bi.biSize = sizeof(BITMAPINFOHEADER); bi.biWidth = Bitmap.bmWidth; bi.biHeight = Bitmap.bmHeight; bi.biPlanes = 1; bi.biBitCount = wBitCount; bi.biCompression = BI_RGB; bi.biSizeImage = 0; bi.biXPelsPerMeter = 0; bi.biYPelsPerMeter = 0; bi.biClrUsed = 0; bi.biClrImportant = 0; dwBmBitsSize = ((Bitmap.bmWidth*wBitCount+31)/32)*4*Bitmap.bmHeight; //为位图内容分配内存/*xxxxxxxx计算位图大小分解一下(解释一下上面的语句)xxxxxxxxxxxxxxxxxxxx //每个扫描行所占的字节数应该为4的整数倍，具体算法为: int biWidth = (Bitmap.bmWidth*wBitCount) / 32; if((Bitmap.bmWidth*wBitCount) % 32) biWidth++; //不是整数倍的加1 biWidth *= 4;//到这里，计算得到的为每个扫描行的字节数。 dwBmBitsSize = biWidth * Bitmap.bmHeight;//得到大小xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/ hDib = GlobalAlloc(GHND,dwBmBitsSize+dwPaletteSize+sizeof(BITMAPINFOHEADER)); lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib); *lpbi = bi; // 处理调色板 hPal = GetStockObject(DEFAULT_PALETTE); if (hPal) { hDC = ::GetDC(NULL); hOldPal=SelectPalette(hDC,(HPALETTE)hPal,FALSE); RealizePalette(hDC); } // 获取该调色板下新的像素值 GetDIBits(hDC,hBitmap,0,(UINT)Bitmap.bmHeight,(LPSTR)lpbi+sizeof(BITMAPINFOHEADER)+dwPaletteSize, (BITMAPINFO *)lpbi,DIB_RGB_COLORS); //恢复调色板 if (hOldPal) { SelectPalette(hDC, hOldPal, TRUE); RealizePalette(hDC); ::ReleaseDC(NULL, hDC); } //创建位图文件 fh=CreateFileA(lpFileName, GENERIC_WRITE,0, NULL, CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL); if (fh==INVALID_HANDLE_VALUE) return FALSE; // 设置位图文件头 bmfHdr.bfType = 0x4D42; // "BM" dwDIBSize=sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)+dwPaletteSize+dwBmBitsSize; bmfHdr.bfSize = dwDIBSize; bmfHdr.bfReserved1 = 0; bmfHdr.bfReserved2 = 0; bmfHdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER)+(DWORD)sizeof(BITMAPINFOHEADER)+dwPaletteSize; // 写入位图文件头 WriteFile(fh, (LPSTR)&bmfHdr, sizeof(BITMAPFILEHEADER), &dwWritten, NULL); // 写入位图文件其余内容 WriteFile(fh, (LPSTR)lpbi, sizeof(BITMAPINFOHEADER)+dwPaletteSize+dwBmBitsSize , &dwWritten, NULL); //清除 GlobalUnlock(hDib); GlobalFree(hDib); CloseHandle(fh); return TRUE;}int _tmain(int argc, _TCHAR* argv[]){CRect rect;GetWindowRect(FindWindow(NULL,L"计算器"),&rect);HBITMAP hMap = CopyScreenToBitmap(rect); SaveBitmapToFile(hMap,"C:\\局部截图.bmp"); //CRect rect;//rect.left = 0;//rect.top = 0;//rect.right = GetSystemMetrics(SM_CXSCREEN);//rect.bottom = GetSystemMetrics(SM_CYSCREEN);//HBITMAP hMap = CopyScreenToBitmap(rect); //SaveBitmapToFile(hMap,"C:\\全屏截图.bmp"); return 0;}
