axWindowsMediaPlayer: Black Screen on looping

问题

I have created a Windows Form Application having axWindowsMediaPlayer control. I haven't created a playlist on it, but I have stored my .mp4 files at a particular location. I pass the path to my next video at Media Ended state. For the first time, the player receives the correct path and play. But for the second video, I can only see a black screen although the player is receiving the correct path to play.

Here is my code for Media Ended State:

private void axWindowsMediaPlayer_PlayStateChange(object sender, AxWMPLib._WMPOCXEvents_PlayStateChangeEvent e)
{
  if(e.newState == 8)
    {
      //Getting jumpTo of selected page
      var selectedElementJumpToValue = MainContentAreaBl.GetSelectedElementValue(_currentId, "jumpTo");
      if (selectedElementJumpToValue != null)
      {
        _currentId = selectedElementJumpToValue;
        if (_currentId != "menu")
        {
          pagination.Text = MainContentAreaBl.GetPaginationText(_currentId);                        
          LaunchPlayer(selectedElementJumpToValue);
        }
        else
        {
          this.Hide();
          this.SendToBack();
          menu.BringToFront();
        }
    }
  }
}

private void LaunchPlayer(string id)
{
  string selectedElementPageTypeValue = MainContentAreaBl.GetSelectedElementPageTypeValue(id);
  var playerFile = Path.Combine(Common.ContentFolderPath, MainContentAreaBl.GetSelectedElementDataPathValue(id));                
  if (selectedElementPageTypeValue == "video")
  {
    InitialiseMediaPlayer();
    axShockwaveFlash.Stop();
    axShockwaveFlash.Visible = false;              
    if (File.Exists(playerFile))               
    {
      axWindowsMediaPlayer.URL = playerFile;
    }               
  }
  else if (selectedElementPageTypeValue == "flash")
  {
    InitialiseShockwaveFlash();
    axWindowsMediaPlayer.close();
    axWindowsMediaPlayer.Visible = false;
    if (File.Exists(playerFile))
    {
      axShockwaveFlash.Movie = playerFile;
      axShockwaveFlash.Play();
    }                
  }
}

private void InitialiseMediaPlayer()
{
  axWindowsMediaPlayer.Visible = true;
  axWindowsMediaPlayer.enableContextMenu = false           
  axWindowsMediaPlayer.uiMode = "none";
  axWindowsMediaPlayer.Dock = DockStyle.Fill;
}

When I debugged my application, I saw Media Player getting the correct path after e.newState == 10 (Ready state). What am I doing wrong?

Edit 1: I found out that after my current video enters into Media Ended state, the player is stopped from playing. Even if I write axWindowsMediaPlayer.ctlControls.play();, it doesn't affect the media player. Is this a bug from in axWindowsMediaPlayer?

回答1:

I have encountered this issue before as well. The most likely cause is that you are giving the command axWindowsMediaPlayer.ctlControls.play(); while the play state is still changing ( after Media Ended, it will change to Ready state). If a command is sent to the player while the play state is changing, it won't do anything. Another possible cause of your error is that sometimes Media State 9 (transitioning) needs to be included with if(e.newState == 8) such that you have if(e.newState == 8 | e.newState==9). I have had cases where it doesn't pick up on State 8 (media ending), possibly because it happens really fast and jumps to transitioning - not completely sure of this cause but I had a player that wasn't moving to the next video in the playlist because of this happening. To solve this I did something like:

  if (e.newState == 8 | e.newState== 9 | e.newState== 10)
            {
                if (e.newState == 8)
                { //Insert your code here
            }

This would vary slightly depending on what you are trying to achieve. Another thing to watch out for is using the PlayStateChange Event to set the Video URL, this causes problems as a result of re-entry problems with WMP - see other posts for further explanation on my last comment: here is a good one and another here. Hope this helps!

来源：https://stackoverflow.com/questions/34677126/axwindowsmediaplayer-black-screen-on-looping

标签

visual-studio-2013

axwindowsmediaplayer