public MediaFileViewModel(MediaFile mediaFile)
 {
     this.mediaFile    = mediaFile;
     SaveFileCommand   = new SaveFileCommand(this);
     IsMediaOpened     = false;
     PlayMediaCommand  = new PlayMediaCommand(this);
     PauseMediaCommand = new PauseMediaCommand(this);
 }
 public MediaFileViewModel()
 {
     mediaFile         = new MediaFile();
     SaveFileCommand   = new SaveFileCommand(this);
     IsMediaOpened     = false;
     PlayMediaCommand  = new PlayMediaCommand(this);
     PauseMediaCommand = new PauseMediaCommand(this);
 }