/// <summary>
/// 建立猜謎View Model.
/// <para>當猜謎使用完畢後需要呼叫PuzzleCenterVM.Close成員方法進行關閉，才能建立新的猜謎</para>
/// </summary>
/// <returns>回傳新的猜謎，若猜謎尚未關閉則回傳NULL</returns>
public PuzzleCenterVM CreatePuzzleCenter()
{
if (_puzzleCenterVM == null ||
_puzzleCenterVM.IsClosed)
{
_puzzleCenterVM = new PuzzleCenterVM();
return(_puzzleCenterVM);
}
return(null);
}
public MainWindowVM()
{
_cmtLoader = new CommentLoader();
_commentColle = new ObservableCollection <CommentVM>();
this.CommentColle = CollectionViewSource.GetDefaultView(_commentColle);
BindingOperations.EnableCollectionSynchronization(_commentColle, _lockCommentColleObj);
_votingCenterVM = null;
_puzzleCenterVM = null;
_authorTable = new Dictionary <string, string>();
_isStopped = true;
_cmtLoader.OnStatusChanged += On_CommetLoader_StatusChanged;
_cmtLoader.OnError += On_CommentLoader_Error;
_cmtLoader.OnCommentsReceive += On_CommentLoader_CommentsReceive;
this.StatusText = "已停止";
}