使用GDI+播放GIF动画

• Download GIFControl - 2.67 KB

Introduction

As passed , there is no convient enough way to play gif using functions provided by Microsoft Windows but you may need a reference of 3rd libs. Well now we have an alternative choice --- to use GDI+ .

Critical code

 

//Here We load a gif image file

void CGIFControl::Load(LPCTSTR sFileName)

{

    m_pImage = new Image(sFileName);

    

    //First of all we should get the number of frame dimensions

    //Images considered by GDI+ as:

    //frames[animation_frame_index][how_many_animation];

    UINT count = m_pImage->GetFrameDimensionsCount();



    //Now we should get the identifiers for the frame dimensions 

    m_pDimensionIDs =new GUID[count];

    m_pImage->GetFrameDimensionsList(m_pDimensionIDs, count);

    

    //For gif image , we only care about animation set#0

    WCHAR strGuid[39];

    StringFromGUID2(m_pDimensionIDs[0], strGuid, 39);

    m_FrameCount = m_pImage->GetFrameCount(&m_pDimensionIDs[0]);



    //PropertyTagFrameDelay is a pre-defined identifier to present frame-delays by GDI+

    UINT TotalBuffer = m_pImage->GetPropertyItemSize(PropertyTagFrameDelay);

    m_pItem = (PropertyItem*)malloc(TotalBuffer);

    m_pImage->GetPropertyItem(PropertyTagFrameDelay,TotalBuffer,m_pItem);

}



//To start play

void CGIFControl::Play()

{

    //Set Current Frame at #0

    m_iCurrentFrame = 0;

    GUID Guid = FrameDimensionTime;

    m_pImage->SelectActiveFrame(&Guid,m_iCurrentFrame);



    //Use Timer

    //NOTE HERE: frame-delay values should be multiply by 10

    SetTimer(1,((UINT*)m_pItem[0].value)[m_iCurrentFrame]  * 10,NULL);



    //Move to the next frame

    ++ m_iCurrentFrame;

    Invalidate(FALSE);

}



//Using timer

void CGIFControl::OnTimer(UINT_PTR nIDEvent)

{

    //Because there will be a new delay value

    KillTimer(nIDEvent);



    //Change Active frame

    GUID Guid = FrameDimensionTime;

    m_pImage->SelectActiveFrame(&Guid,m_iCurrentFrame);



    //New timer

    SetTimer(1,((UINT*)m_pItem[0].value)[m_iCurrentFrame] * 10,NULL);



    //Again move to the next

    m_iCurrentFrame = (++ m_iCurrentFrame) % m_FrameCount;

    Invalidate(FALSE);

}



//Finally simply draw

g.DrawImage(m_pImage,rcClient.left,rcClient.top,rcClient.Width(),rcClient.Height());

//Will present the current frame

That's all the core.

 

Using the code

 

Simple usage:

LinaBot::CommonCtrl::CGIFControl* pCtrl = new LinaBot::CommonCtrl::CGIFControl;
pCtrl->Create(rcCreate,TopWindow,c.wData.nID);
pCtrl->Load(GetSkinFileName(c.wData.BackGround));
pCtrl->SetURL(c.wData.sURL);
pCtrl->Play();