ObservableCollection<UserListViewModel> users = new ObservableCollection<UserListViewModel>();
        public ObservableCollection<UserListViewModel> Users
        {
            get { return users; }
            set { users = value; }
        }

        /// <summary>    
        /// 开启监听线程     
        /// </summary>      
        private void openListeningThread()
        {
            isRun = true;
            Thread t = new Thread(new ThreadStart(() =>
            {
                IPEndPoint ipEnd = new IPEndPoint(broadIPAddress, lanPort);
                try
                {
                    while (isRun)
                    {
                        try
                        {
                            byte[] recInfo = listenClient.Receive(ref ipEnd);  //接受内容,存储到byte数组中              
                            DealWithAcceptedInfo(recInfo); //处理接收到的数据                
                        }
                        catch (Exception ex) { MessageBox.Show(ex.Message); }
                    } listenClient.Close(); isRun = false;
                }
                catch (SocketException se) { throw new SocketException(); }  //捕捉试图访问套接字时发生错误。      
                catch (ObjectDisposedException oe) { throw new ObjectDisposedException(oe.Message); } //捕捉Socket 已关闭        
                catch (InvalidOperationException pe) { throw new InvalidOperationException(pe.Message); } //捕捉试图不使用 Blocking 属性更改阻止模式。   
                catch (Exception ex) { throw new Exception(ex.Message); }
            }));

            t.Start();
        }

        /// <summary>        
        /// 方法：处理接到的数据       
        /// </summary>        
        private void DealWithAcceptedInfo(byte[] recData)
        {
            BinaryFormatter formatter = new BinaryFormatter();
            MessageFlag recvMessageFlag;

            MemoryStream ms = new MemoryStream(recData);
            try { recvMessageFlag = (MessageFlag)formatter.Deserialize(ms); }
            catch (SerializationException e) { throw; }

            UserListViewModel uListViewModel = new UserListViewModel(new UserDetailModel { MyIP = recvMessageFlag.UserIP, MyName = recvMessageFlag.UserName });

            switch (recvMessageFlag.Flag)
            {
                case "0x00":
                    //这里很关键，当检测到一个新的用户上线，那么我们需要给这个新用户发送自己的机器消息，以便新用户能够自动添加进列表中。
                    SendInfoOnline(recvMessageFlag.UserIP);
                    
                    if (!list.Contains(uListViewModel.MyInfo))
                    {
                        list.Add(uListViewModel.MyInfo);
                        Users.Add(uListViewModel);
                    }

                    break;
                case "0x01":
                    //AddTextBox(, int titleOrContentFlag, int selfOrOthersFlag);
                    //AddTextBox(string info, int titleOrContentFlag, int selfOrOthersFlag);
                    break;
                case "0x02":

                    break;
                case "0x03":
                    if (list.Contains(uListViewModel.MyInfo))
                    {
                       // list.Remove(uListViewModel.MyInfo);
                        Users.Remove(uListViewModel);
                    }
                    break;
                default: break;
            }
        }

public class AsyncObservableCollection<T> : ObservableCollection<T>
{
    //获取当前线程的SynchronizationContext对象
    private SynchronizationContext _synchronizationContext = SynchronizationContext.Current;
    public AsyncObservableCollection() { }
    public AsyncObservableCollection(IEnumerable<T> list) : base(list) { }
    protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
    {
          
        if (SynchronizationContext.Current == _synchronizationContext)
        {
            //如果操作发生在同一个线程中，不需要进行跨线程执行         
            RaiseCollectionChanged(e);
        }
        else
        {
            //如果不是发生在同一个线程中
            //准确说来，这里是在一个非UI线程中，需要进行UI的更新所进行的操作         
            _synchronizationContext.Post(RaiseCollectionChanged, e);
        }
    }
    private void RaiseCollectionChanged(object param)
    {
        // 执行         
        base.OnCollectionChanged((NotifyCollectionChangedEventArgs)param);
    }
    protected override void OnPropertyChanged(PropertyChangedEventArgs e)
    {
        if (SynchronizationContext.Current == _synchronizationContext)
        {
            // Execute the PropertyChanged event on the current thread             
            RaisePropertyChanged(e);
        }
        else
        {
            // Post the PropertyChanged event on the creator thread             
            _synchronizationContext.Post(RaisePropertyChanged, e);
        }
    }
    private void RaisePropertyChanged(object param)
    {
        // We are in the creator thread, call the base implementation directly         
        base.OnPropertyChanged((PropertyChangedEventArgs)param);
    }
}

        AsyncObservableCollection<UserListViewModel> users = new AsyncObservableCollection<UserListViewModel>();
        public AsyncObservableCollection<UserListViewModel> Users
        {
            get { return users; }
            set { users = value; }
        }