在中Visual Studio .NET 2003利用DirectShow播放媒体文件(四)

// IDC_VW_FRAME控件Picture Control主要作用是控制Vedio Window的显示位置

void CPlayWndDlg::MoveVideoWindow(void)

{

    IVideoWindow* pVideoWinow = NULL;

    if(m_pGraph)

    {

       m_pGraph->QueryInterface(IID_IVideoWindow, (void **)&pVideoWinow);

       CRect rc;

       GetDlgItem(IDC_VW_FRAME)->GetWindowRect(rc);

       ScreenToClient(rc);

       pVideoWinow->SetWindowPosition(rc.left, rc.top, rc.Width(), rc.Height());

       pVideoWinow->Release();

       pVideoWinow = NULL;

    }

}

void CPlayWndDlg::CleanUp(void)

{

    long levCode;

    IVideoWindow *pVidWin = NULL;

    if(!m_pGraph)

       return;

    m_pGraph->QueryInterface(IID_IVideoWindow, (void **)&pVidWin);

    m_pEvent->WaitForCompletion(INFINITE, &levCode);

    pVidWin->put_Visible(OAFALSE);

    pVidWin->Release();

    m_pMediaSeeking->Release();

    m_pMediaControl->Release();

    m_pEvent->Release();

    m_pGraph->Release();

    m_pMediaSeeking = NULL;

    m_pMediaControl = NULL;

    m_pEvent = NULL;

    m_pGraph = NULL;

    UpdateData(FALSE);

    CClientDC dc(GetDlgItem(IDC_VW_FRAME));

    dc.SetBkColor(RGB(0,0,0));

    CRect rc;

    GetDlgItem(IDC_VW_FRAME)->GetClientRect(rc);

    ClientToScreen(rc);

    dc.FillRect(rc, CBrush::FromHandle((HBRUSH)GetStockObject(BLACK_BRUSH)));

    Invalidate();

}

BOOL CPlayWndDlg::Stop(void)

{

    IVideoWindow *pVidWin = NULL;

    HRESULT hr;

    if(m_pMediaControl)

    {

       LONGLONG pos = 0;

       hr = m_pMediaControl->Stop();

       hr = m_pMediaSeeking->SetPositions(&pos, AM_SEEKING_AbsolutePositioning ,

           &pos, AM_SEEKING_NoPositioning);

       m_pGraph->QueryInterface(IID_IVideoWindow, (void **)&pVidWin);

       pVidWin->put_Visible(OAFALSE);

       m_isPlaying = FALSE;

       GetDlgItem(IDC_PLAY_BUTTON)->EnableWindow(TRUE);

       GetDlgItem(IDC_PAUSE_BUTTON)->EnableWindow(FALSE);

       pVidWin->Release();

       long levCode;

       m_pEvent->WaitForCompletion(INFINITE, &levCode);

       m_pMediaControl->Release();

       return TRUE;

    }

    return FALSE;

}

BOOL CPlayWndDlg::Play(void)

{

    // 运行

    IVideoWindow *pVidWin = NULL;

    if(m_pGraph)

    {

       m_pGraph->QueryInterface(IID_IVideoWindow, (void **)&pVidWin);

       pVidWin->put_Visible(OATRUE);

       m_pGraph->QueryInterface(IID_IMediaControl, (void **)&m_pMediaControl);

       m_pMediaControl->Run();

       m_isPlaying = TRUE;

       GetDlgItem(IDC_PLAY_BUTTON)->EnableWindow(FALSE);

       GetDlgItem(IDC_PAUSE_BUTTON)->EnableWindow(TRUE);

       return TRUE;

    }

    return FALSE;

}