//打开位图文件,得到位图句柄
HBITMAP OpenBmpFile(HDC hDC, LPSTR lpszFileName)
{
HBITMAP hBmp = NULL;
//读位图文件,得到位图句柄
HANDLE hFile = CreateFile(
lpszFileName,
GENERIC_READ,
FILE_SHARE_READ,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);
if(hFile == INVALID_HANDLE_VALUE)
return NULL;
//读位图文件头
BITMAPFILEHEADER bmpFileHeader;
DWORD dwNumberOfBytesRead;
if(ReadFile(hFile, (LPVOID)&bmpFileHeader, sizeof(BITMAPFILEHEADER), &dwNumberOfBytesRead, NULL) == 0)
{
CloseHandle(hFile);
return NULL;
}
//读位图信息
BITMAPINFO *pBmpInfo = new BITMAPINFO;
if(ReadFile(hFile, pBmpInfo, sizeof(BITMAPINFOHEADER), &dwNumberOfBytesRead, NULL) == 0)
{
CloseHandle(hFile);
return NULL;
}
//读位图数据
LPVOID pBmpData;
//创建DIB位图句柄
hBmp = CreateDIBSection(hDC, pBmpInfo, DIB_PAL_COLORS, &pBmpData, NULL, 0);
if(hBmp == NULL)
{
DWORD dwErr = GetLastError();
return NULL;
}
else //读位图数据
if(ReadFile(hFile, pBmpData, pBmpInfo->bmiHeader.biSizeImage, &dwNumberOfBytesRead, NULL) == 0)
{
CloseHandle(hFile);
return NULL;
}
CloseHandle(hFile);
return hBmp;
}
//下面的代码是把一张位图保存于文件中,参考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);
//打开位图文件
HBITMAP hBmp = OpenBmpFile(hDC, "d:\temp\6370烧写\6484884.bmp");
SelectObject(hMemDC, hBmp);
//在位图上写字
RECT rect = {50, 50, 200, 200};
SetBkMode(hMemDC, TRANSPARENT);
DrawText(hMemDC, "你好", -1, &rect, DT_VCENTER);
//保存位图到文件
PBITMAPINFO pBmpInfo = CreateBitmapInfoStruct(GetSafeHwnd(), hBmp);
CreateBMPFile(GetSafeHwnd(), "Test.bmp", pBmpInfo, hBmp, hDC);
DeleteDC(hMemDC);
DeleteObject(hBmp);
}