加载jpg图片

 

原文地址:
http://blog.csdn.net/qingdaoxuelei/article/details/4387590

HANDLE hFile = CreateFile(szImagePath, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL); //从指定的路径szImagePath中读取文件句柄
 DWORD dwFileSize = GetFileSize(hFile, NULL); //获得图片文件的大小，用来分配全局内存
 HGLOBAL hImageMemory = GlobalAlloc(GMEM_MOVEABLE, dwFileSize); //给图片分配全局内存
 void *pImageMemory = GlobalLock(hImageMemory); //锁定内存
 DWORD dwReadedSize;       //保存实际读取的文件大小
 ReadFile(hFile, pImageMemory, dwFileSize, &dwReadedSize, NULL); //读取图片到全局内存当中
 GlobalUnlock(hImageMemory); //解锁内存
 CloseHandle(hFile); //关闭文件句柄

 IStream *pIStream;//创建一个IStream接口指针，用来保存图片流
 IPicture *pIPicture;//创建一个IPicture接口指针，表示图片对象
 CreateStreamOnHGlobal(hImageMemory, false, &pIStream) // 用全局内存初使化IStream接口指针
  OleLoadPicture(pIStream, 0, false, IID_IPicture, (LPVOID*)&(pIPicture));//用OleLoadPicture获得IPicture接口指针

 //得到IPicture COM接口对象后，你就可以进行获得图片信息、显示图片等操作
 OLE_XSIZE_HIMETRIC hmWidth;
 OLE_YSIZE_HIMETRIC hmHeight;
 pIPicture->get_Width(&hmWidth); //用接口方法获得图片的宽和高
 pIPicture->get_Height(&hmHeight);

 pIPicture->Render(hDC, 0, 0, 100, 100, 0, hmHeight, hmWidth,-hmHeight,NULL); //在指定的DC上绘出图片

 GlobalFree(hImageMemory); //释放全局内存

 pIStream->Release(); //释放pIStream
 pIPicture->Release();  //释放pIPicture