Serialization of the Image class

Using the image class provided by the GDI + graphics device interface We can easily display pictures of file formats such as JPEG, GIF, and so on, but the drawback is that the image class does not provide the ability to serialize data, if you want to move from JPEG, The image data that is read in the GIF format file is saved to the application document that we developed, and we can read the saved picture data from the document and display it correctly, we must implement the serialization of the image class data. If you have a member pointer variable m_pimage to the image class in your document class that is used to display the picture, then add the following code to the serialization function serialize (carchive& AR) of the document class to achieve m_ Serialization of the picture data that the pimage points to:if (AR. IsStoring ())
{
Hglobal M_hmem = GlobalAlloc (gmem_moveable, 0);
IStream *pstm=null;
CreateStreamOnHGlobal (M_hmem, TRUE, &pstm);
CLSID clsid;
Uses_conversion;
Getcodecclsid (a2w ("Image/bmp"), &clsid);
M_pimage->save (Pstm,&clsid,null);
if (pstm==null)
Return
Large_integer libeggining = {0};
Pstm->seek (libeggining, Stream_seek_set, NULL);
DWORD wtemp=globalsize (M_HMEM);
Lpbyte lpdata = (lpbyte) globallock (M_HMEM);
Ar << wtemp;
Ar. Write (lpdata,wtemp);
Pstm->release ();
GlobalUnlock (M_HMEM);
}
Else
{
DWORD wtemp;
Ar >> wtemp;
Hglobal M_hmem = GlobalAlloc (gmem_fixed, wtemp);
if (M_hmem = NULL)
Return
IStream *pstm=null;
CreateStreamOnHGlobal (m_hmem,false,&pstm);
if (pstm==null)
Return
byte* Pmem = (byte*) globallock (M_HMEM);
Ar. Read (pmem,wtemp);
if (m_pimage) {
Delete M_pimage;
M_pimage = NULL;
}
using namespace Gdiplus;
M_pimage = Image::fromstream (pstm, FALSE);
Pstm->release ();
GlobalUnlock (M_HMEM);
Note that GlobalFree (M_HMEM) cannot be added here, otherwise the picture will not show up.The implementation code for the function Getcodecclsid is as follows:int GetCodecClsid(const WCHAR* format, CLSID* pClsid)
{
　 UINT　num = 0;　　　　　// number of image encoders
　 UINT　size = 0;　　　　 // size of the image encoder array in bytes
　 using namespace Gdiplus;
　 ImageCodecInfo* pImageCodecInfo = NULL;
　 GetImageEncodersSize(&num, &size);
　 if(size == 0)
　　　return -1;　// Failure
　 pImageCodecInfo = (ImageCodecInfo*)(malloc(size));
　 if(pImageCodecInfo == NULL)
　　　return -1;　// Failure
　 GetImageEncoders(num, size, pImageCodecInfo);
　 for(UINT j = 0; j < num; ++j)
　 {
　　　if( wcscmp(pImageCodecInfo[j].MimeType, format) == 0 )
　　　{
　　　　 *pClsid = pImageCodecInfo[j].Clsid;
　　　　 return j;　// Success
　　　}　　
　 } // for
　 return -1;　// Failure
} // GetCodecClsidParameter format is used to illustrate the format of the image data, you can take the following values: "Image/bmp" (bitmap format), "Image/jpeg" (JPEG format), "Image/gif" (gif format) and so on.