//打開位圖文件,得到位圖句柄 HBITMAP OpenBmpFile(HDC hDC, LPSTR lpszFileName) { HBITMAP hBmp = NULL; //讀位圖文件,得到位圖句柄 HANDLE hFile = CreateFile( lpszFileName, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL); if(hFile == INVALID_HANDLE_VALUE) return NULL; //讀位圖文件頭 BITMAPFILEHEADER bmpFileHeader; DWORD dwNumberOfBytesRead; if(ReadFile(hFile, (LPVOID)&bmpFileHeader, sizeof(BITMAPFILEHEADER), &dwNumberOfBytesRead, NULL) == 0) { CloseHandle(hFile); return NULL; } //讀位圖信息 BITMAPINFO *pBmpInfo = new BITMAPINFO; if(ReadFile(hFile, pBmpInfo, sizeof(BITMAPINFOHEADER), &dwNumberOfBytesRead, NULL) == 0) { CloseHandle(hFile); return NULL; } //讀位圖數據 LPVOID pBmpData; //創建DIB位圖句柄 hBmp = CreateDIBSection(hDC, pBmpInfo, DIB_PAL_COLORS, &pBmpData, NULL, 0); if(hBmp == NULL) { DWORD dwErr = GetLastError(); return NULL; } else //讀位圖數據 if(ReadFile(hFile, pBmpData, pBmpInfo->bmiHeader.biSizeImage, &dwNumberOfBytesRead, NULL) == 0) { CloseHandle(hFile); return NULL; } CloseHandle(hFile); return hBmp; } //下面的代碼是把一張位圖保存於文件中,參考MSDN PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp) { BITMAP bmp; PBITMAPINFO pbmi; WORD cClrBits; // Retrieve the bitmap's color format, width, and height. if (!GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp)) return NULL; // Convert the color format to a count of bits. cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel); if (cClrBits == 1) cClrBits = 1; else if (cClrBits <= 4) cClrBits = 4; else if (cClrBits <= 8) cClrBits = 8; else if (cClrBits <= 16) cClrBits = 16; else if (cClrBits <= 24) cClrBits = 24; else cClrBits = 32; // Allocate memory for the BITMAPINFO structure. (This structure // contains a BITMAPINFOHEADER structure and an array of RGBQUAD // data structures.) if (cClrBits != 24) pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * (1<< cClrBits)); // There is no RGBQUAD array for the 24-bit-per-pixel format. else pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER)); // Initialize the fields in the BITMAPINFO structure. pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER); pbmi->bmiHeader.biWidth = bmp.bmWidth; pbmi->bmiHeader.biHeight = bmp.bmHeight; pbmi->bmiHeader.biPlanes = bmp.bmPlanes; pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel; if (cClrBits < 24) pbmi->bmiHeader.biClrUsed = (1<<cClrBits); // If the bitmap is not compressed, set the BI_RGB flag. pbmi->bmiHeader.biCompression = BI_RGB; // Compute the number of bytes in the array of color // indices and store the result in biSizeImage. // For Windows NT/2000, the width must be DWORD aligned unless // the bitmap is RLE compressed. This example shows this. // For Windows 95/98, the width must be WORD aligned unless the // bitmap is RLE compressed. pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31) & ~31) /8 * pbmi->bmiHeader.biHeight; // Set biClrImportant to 0, indicating that all of the // device colors are important. pbmi->bmiHeader.biClrImportant = 0; return pbmi; } void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP, HDC hDC) { HANDLE hf; // file handle BITMAPFILEHEADER hdr; // bitmap file-header PBITMAPINFOHEADER pbih; // bitmap info-header LPBYTE lpBits; // memory pointer DWORD dwTotal; // total count of bytes DWORD cb; // incremental count of bytes BYTE *hp; // byte pointer DWORD dwTmp; pbih = (PBITMAPINFOHEADER) pbi; lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage); if (!lpBits) return ; // Retrieve the color table (RGBQUAD array) and the bits // (array of palette indices) from the DIB. if (!GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi, DIB_RGB_COLORS)) { return ; } // Create the .BMP file. hf = CreateFile(pszFile, GENERIC_READ | GENERIC_WRITE, (DWORD) 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, (HANDLE) NULL); if (hf == INVALID_HANDLE_VALUE) return ; hdr.bfType = 0x4d42; // 0x42 = "B" 0x4d = "M" // Compute the size of the entire file. hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed * sizeof(RGBQUAD) + pbih->biSizeImage); hdr.bfReserved1 = 0; hdr.bfReserved2 = 0; // Compute the offset to the array of color indices. hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed * sizeof (RGBQUAD); // Copy the BITMAPFILEHEADER into the .BMP file. if (!WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp, NULL)) { return ; } // Copy the BITMAPINFOHEADER and RGBQUAD array into the file. if (!WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) + pbih->biClrUsed * sizeof (RGBQUAD), (LPDWORD) &dwTmp, ( NULL))) return ; // Copy the array of color indices into the .BMP file. dwTotal = cb = pbih->biSizeImage; hp = lpBits; if (!WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL)) return ; // Close the .BMP file. if (!CloseHandle(hf)) return ; GlobalFree((HGLOBAL)lpBits); } void CTextOnbmpDlg::OnButton1() { // TODO: Add your control notification handler code here // TODO: Add your control notification handler code here HDC hDC = ::GetDC(GetSafeHwnd()); HDC hMemDC = CreateCompatibleDC(hDC); //打開位圖文件 HBITMAP hBmp = OpenBmpFile(hDC, "d:\\temp\\6370燒寫\\6484884.bmp"); SelectObject(hMemDC, hBmp); //在位圖上寫字 RECT rect = {50, 50, 200, 200}; SetBkMode(hMemDC, TRANSPARENT); DrawText(hMemDC, "你好", -1, &rect, DT_VCENTER); //保存位圖到文件 PBITMAPINFO pBmpInfo = CreateBitmapInfoStruct(GetSafeHwnd(), hBmp); CreateBMPFile(GetSafeHwnd(), "Test.bmp", pBmpInfo, hBmp, hDC); DeleteDC(hMemDC); DeleteObject(hBmp); }
