将位图写入磁盘

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我是靠谱客的博主和谐香烟，最近开发中收集的这篇文章主要介绍将位图写入磁盘，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

void WriteBMPFile(HBITMAP hBitmap, LPSTR filename, HDC hDC)
{
BITMAP bmp;
    PBITMAPINFO pbmi;
    WORD cClrBits;
    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;
    // create the bitmapinfo header information

    if (!GetObject( hBitmap, sizeof(BITMAP), (LPTSTR)&bmp))
    {
        return;
    }

// 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.

    if (cClrBits != 24)
    pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * (1<<cClrBits));
    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.
pbmi->bmiHeader.biSizeImage = (pbmi->bmiHeader.biWidth + 7) /8 * pbmi->bmiHeader.biHeight * cClrBits;

// Set biClrImportant to 0, indicating that all of the

// device colors are important.
pbmi->bmiHeader.biClrImportant = 0;

    // now open file and save the data
    pbih = (PBITMAPINFOHEADER) pbmi;
    lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);

    if (!lpBits)
    {
        return;
    }

// Retrieve the color table (RGBQUAD array) and the bits

    if (!GetDIBits(hDC, HBITMAP(hBitmap), 0, (WORD) pbih->biHeight, lpBits, pbmi, DIB_RGB_COLORS))
    {
        return;
    }

// Create the .BMP file.

    hf = CreateFile(filename, 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;
    }

// Free memory.

GlobalFree((HGLOBAL)lpBits);
}

测试代码：

void OnDraw(CDC* pDC)
{
CTestBMPDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
// TODO: add draw code for native data here

CRect rect;
GetClientRect(&rect);

CDC ImageDC;
ImageDC.CreateCompatibleDC(pDC);

CBitmap bmp,*oldbmp;
bmp.CreateCompatibleBitmap(pDC,rect.Width(),rect.Height());
oldbmp = ImageDC.SelectObject(&bmp);

ImageDC.FillSolidRect(rect, pDC->GetBkColor());

ImageDC.MoveTo(10, 10);
ImageDC.LineTo(300, 300);

WriteBMPFile((HBITMAP)bmp.GetSafeHandle(),"C://1.bmp",ImageDC.m_hDC);

pDC->BitBlt(0,0,rect.Width(),rect.Height(),&ImageDC,0,0,SRCCOPY);