Gdi+ 加载Gif图片(BYTE*转为IStream)

今天工作中遇到GDI+加载图片流的问题，网上找了很多资料都不行，绘制其他帧总是模糊，，

网上的方法代码如下：

注：pImageData是BYTE*类型 ,dImageLen是DWORD类型;

HGLOBAL m_hMem = GlobalAlloc(GMEM_FIXED, dImageLen);
BYTE* pmem = (BYTE*)GlobalLock(m_hMem);
memcpy(pmem,pImageData,dImageLen);
IStream* pstm;
HRESULT ht =  CreateStreamOnHGlobal(m_hMem,FALSE,&pstm);
if (ht != S_OK)
{
	GlobalFree(m_hMem);
	return ;
}
m_pImage=Gdiplus::Image::FromStream(pstm);
GlobalUnlock(m_hMem);   

pstm->Release();
GlobalFree(m_hMem); 

if (m_pImage)
{
	UINT count = m_pImage->GetFrameDimensionsCount();
	if (count > 0 && m_pImage->GetLastStatus() == 0)
	{
		m_pDimensionIDs = new GUID[count];
		m_pImage->GetFrameDimensionsList(m_pDimensionIDs, count);
		WCHAR strGuid[39];
		StringFromGUID2(m_pDimensionIDs[0], strGuid, 39);
		m_FrameCount = m_pImage->GetFrameCount(&m_pDimensionIDs[0]);
		UINT TotalBuffer = m_pImage->GetPropertyItemSize(PropertyTagFrameDelay);
		m_pItem = (Gdiplus::PropertyItem*)malloc(TotalBuffer);
		m_pImage->GetPropertyItem(PropertyTagFrameDelay, TotalBuffer, m_pItem);
		m_bStatOK = TRUE;
	}
}

　总是绘制出现问题后自己找了方法解决问题，代码如下：

注：m_pstream是类成员，在类析构的时候释放 ，，，pImageData是BYTE*类型 ,dImageLen是DWORD类型;

if(CreateStreamOnHGlobal(NULL, TRUE, &m_pStream) == S_OK)
	{
		ULONG ulWritten = 0;
		m_pStream->Write(pImageData, dImageLen, &ulWritten);

		//Rewind the argument stream;
		LARGE_INTEGER lInt;
		lInt.QuadPart = 0;
		m_pStream->Seek(lInt, STREAM_SEEK_SET, NULL);

		//Read the lenght of the argument stream;
		STATSTG statSTG;
		long dwResult = m_pStream->Stat(&statSTG, STATFLAG_DEFAULT);
		if(dwResult != S_OK)
		{
			return ;
		}
		m_pImage=Gdiplus::Image::FromStream(m_pStream);
		if (m_pImage)
		{
			UINT count = m_pImage->GetFrameDimensionsCount();
			if (count > 0 && m_pImage->GetLastStatus() == 0)
			{
				m_pDimensionIDs = new GUID[count];
				m_pImage->GetFrameDimensionsList(m_pDimensionIDs, count);
				WCHAR strGuid[39];
				StringFromGUID2(m_pDimensionIDs[0], strGuid, 39);
				m_FrameCount = m_pImage->GetFrameCount(&m_pDimensionIDs[0]);
				UINT TotalBuffer = m_pImage->GetPropertyItemSize(PropertyTagFrameDelay);
				m_pItem = (Gdiplus::PropertyItem*)malloc(TotalBuffer);
				m_pImage->GetPropertyItem(PropertyTagFrameDelay, TotalBuffer, m_pItem);
				m_bStatOK = TRUE;
			}
		}
	}

这样通过定时器绘制其他帧就没有图片不成像问题

DrawGif(HDC hDC, const RECT& rc)
{
	if (NULL == m_pItem)
		return 0;

    m_pImage->SelectActiveFrame(&Gdiplus::FrameDimensionTime, m_iCurrentFrame);

    unsigned msec = ((int*)m_pItem->value)[m_iCurrentFrame] * 10;

	Graphics g( hDC );
	g.SetSmoothingMode(Gdiplus::SmoothingModeHighQuality);
	g.DrawImage( m_pImage, rc.left, rc.top, rc.right-rc.left, rc.bottom - rc.top );

    return msec;
}