After defined a Windows Media Player control
In the file joined the # include "CWMPPlayer4. H"
And defines the
Public:
CWMPPlayer4 m_MediaPlayer;

Why would the following function call m_MediaPlayer hint is undefined identifiers?

Void CwangluoMFC2Dlg: : DoDataExchange (CDataExchange * symbol)
{
CDialogEx: : DoDataExchange (symbol);

DDX_Control (symbol, IDC_OCX1 m_MediaPlayer);//here call times wrong undefined identifiers
}