仅使用Win32将HBITMAP保存为* .bmp文件

我在纯Win32项目中有一个HBITMAP(不使用外部库)。 我可以使用Winapi和/或CRT函数将它导出到* .bmp文件,所以我不会产生任何额外的依赖关系?

Solutions Collecting From Web of "仅使用Win32将HBITMAP保存为* .bmp文件"

没有API直接保存到文件中,因为通常情况下,具有位图句柄并不意味着您可以直接访问位图数据。 您的解决方案是将位图复制到另一个具有数据访问(DIB)的位图,然后使用它将数据写入文件。

您通常要么使用CreateDIBSection创建另一个位图,要么使用GetDIBits获取位图数据。

CreateFileWriteFile将数据写入文件。

你写: BITMAPFILEHEADER ,然后BITMAPINFOHEADER ,然后调色板(当比特/像素超过8时通常没有),然后是数据本身。

也可以看看:

  • C ++:Hbitmap / BITMAP到.bmp文件 ( 这个答案 )
  • 在C Win32中使用hBitmap = CreateDIBSection()保存.bmp文件
  • 在MSDN上存储图像

代码

这是来自MSDN文章的代码( 请注意 ,您需要定义errhandler()函数):

 PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp) { BITMAP bmp; PBITMAPINFO pbmi; WORD cClrBits; // Retrieve the bitmap color format, width, and height. if (!GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp)) errhandler("GetObject", hwnd); // 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 these formats: 24-bit-per-pixel or 32-bit-per-pixel 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. // The width must be DWORD 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) errhandler("GlobalAlloc", hwnd); // 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)) { errhandler("GetDIBits", hwnd); } // 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) errhandler("CreateFile", hwnd); 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)) { errhandler("WriteFile", hwnd); } // Copy the BITMAPINFOHEADER and RGBQUAD array into the file. if (!WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) + pbih->biClrUsed * sizeof (RGBQUAD), (LPDWORD) &dwTmp, ( NULL))) errhandler("WriteFile", hwnd); // 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)) errhandler("WriteFile", hwnd); // Close the .BMP file. if (!CloseHandle(hf)) errhandler("CloseHandle", hwnd); // Free memory. GlobalFree((HGLOBAL)lpBits); } 

我将在这里留下这个自我包含的概念证明,因为我可能需要稍后查看它,因为它不明显。 它将桌面窗口的屏幕截图保存到bitmap.bmp中:

 #include <Windows.h> #include <stdio.h> #include <assert.h> /* forward declarations */ PBITMAPINFO CreateBitmapInfoStruct(HBITMAP); void CreateBMPFile(LPTSTR pszFile, HBITMAP hBMP) int main(int argc, char **argv); PBITMAPINFO CreateBitmapInfoStruct(HBITMAP hBmp) { BITMAP bmp; PBITMAPINFO pbmi; WORD cClrBits; // Retrieve the bitmap color format, width, and height. assert(GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp)); // 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 these formats: 24-bit-per-pixel or 32-bit-per-pixel 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. // The width must be DWORD 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(LPTSTR pszFile, HBITMAP hBMP) { 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; PBITMAPINFO pbi; HDC hDC; hDC = CreateCompatibleDC(GetWindowDC(GetDesktopWindow())); SelectObject(hDC, hBMP); pbi = CreateBitmapInfoStruct(hBMP); pbih = (PBITMAPINFOHEADER) pbi; lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage); assert(lpBits) ; // Retrieve the color table (RGBQUAD array) and the bits // (array of palette indices) from the DIB. assert(GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi, DIB_RGB_COLORS)); // Create the .BMP file. hf = CreateFile(pszFile, GENERIC_READ | GENERIC_WRITE, (DWORD) 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, (HANDLE) NULL); assert(hf != INVALID_HANDLE_VALUE) ; 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. assert(WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp, NULL)); // Copy the BITMAPINFOHEADER and RGBQUAD array into the file. assert(WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) + pbih->biClrUsed * sizeof (RGBQUAD), (LPDWORD) &dwTmp, ( NULL))); // Copy the array of color indices into the .BMP file. dwTotal = cb = pbih->biSizeImage; hp = lpBits; assert(WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL)); // Close the .BMP file. assert(CloseHandle(hf)); // Free memory. GlobalFree((HGLOBAL)lpBits); } int main(int argc, char **argv) { HWND hwnd; HDC hdc[2]; HBITMAP hbitmap; RECT rect; hwnd = GetDesktopWindow(); GetClientRect(hwnd, &rect); hdc[0] = GetWindowDC(hwnd); hbitmap = CreateCompatibleBitmap(hdc[0], rect.right, rect.bottom); hdc[1] = CreateCompatibleDC(hdc[0]); SelectObject(hdc[1], hbitmap); BitBlt ( hdc[1], 0, 0, rect.right, rect.bottom, hdc[0], 0, 0, SRCCOPY ); CreateBMPFile("bitmap.bmp", hbitmap); }