public void AddItem(Musics musics)
{
PlayLine line = Lines
.Where(p => p.Musics.Id == musics.Id)
.FirstOrDefault();
if (line == null)
{
Lines.Add(new PlayLine
{
Musics = musics
}
);
}
}
public void RemoveLine(Musics musics) => Lines.RemoveAll(l => l.Musics.Id == musics.Id);