I am not able to invoke an event handler using a lambda expression in C#

using AxWMPLib;
using WMPLib;

public static AxWMPLib.AxWindowsMediaPlayer wplayer = new AxWMPLib.AxWindowsMediaPlayer();
public static WMPLib.WindowsMediaPlayer wplayer_1 = new WMPLib.WindowsMediaPlayer();

//state changed event handler
wplayer_1.PlayStateChange += new WMPLib._WMPOCXEvents_PlayStateChangeEventHandler((NewState) => wplayer_playstate_change(NewState, media, playlist));

wplayer.PlayStateChange += new AxWMPLib._WMPOCXEvents_PlayStateChangeEventHandler((NewState) =>  wplayer_playstate_change(NewState,media,playlist));

private void wplayer_playstate_change(int NewState, OmnisignMedia media, IEnumerable<OmnisignMedia> partialList)
{
}