网络播放器的改写问题！！！

Question

设置全屏的：
BOOL DShow_PutFullScreen(HWND drain,HWND phWnd)
{
LONG mode;
if(pIVWindow==NULL)
{   MessageBox(NULL,"Can't Toggle Full Screen.\nMay be you haven't selected a video to play.","FAILED",MB_OK);
return FALSE;
}
pIVWindow->get_FullScreenMode(&mode);
if(mode==OAFALSE){
pIVWindow->get_MessageDrain((OAHWND *)(&drain));
pIVWindow->put_MessageDrain((OAHWND )phWnd);
mode=OATRUE;
pIVWindow->put_FullScreenMode(mode);
}
else {
mode=OAFALSE;
pIVWindow->put_MessageDrain((OAHWND)drain);
pIVWindow->put_FullScreenMode(mode);
}
return TRUE;
}

Answer 1

//seeking bar
void CMYDlg::OnReleasedcaptureSlider(NMHDR* pNMHDR, LRESULT* pResult) 
{   
    LONG loffset;
    CurPos=m_CSliderCtrl.GetPos();
    loffset=(LONG)(FileLength*CurPos/SliderRange);
                      //SliderRange为Slider 的长度
    DShow_Buf2Zero(); //清空缓冲区
    if (f.m_hFile!= (UINT)CFile::hFileNull) 
       {
f.SeekToBegin();
         f.Seek(loffset,CFile::begin);
        }
    *pResult = 0;
}(只）用IMediaSeeking 接口不行的吧。因为有个读文件添数据的线程，我想在seeking的时候改变文件指针是不是可以了，结果出问题了