private async Task Search(bool isFirst)
        {
            if (Form.HasError || mIsSeaching)
            {
                return;
            }
            if (isFirst != true && mIsLoadedAllData)
            {
                return;
            }
            IsPageDataLoading = !isFirst;
            mIsSeaching = true;
            if (isFirst)
            {
                mIsLoadedAllData = false;
                mCacheSearchForm = Form.Clone() as SearchForm;
                this.Biaoshis.Clear();
            }

            try
            {
                var jhTypes = mCacheSearchForm.JianghuTypes.Split(new[] { "," }, StringSplitOptions.RemoveEmptyEntries)
                    .Select(a => (BangpaiType)Enum.Parse(typeof(BangpaiType), a)).ToArray();
                var rv = await Task.Run<CombinationBiaoshiData>(() =>
                {
                    return mBiaoshiMgmtService.SearchBiaoshiByMengzhu(jhTypes, mCacheSearchForm.StartDate,
                        mCacheSearchForm.EndDate, mCacheSearchForm.SiteUserName, mCacheSearchForm.IsTimeRangeRequired,
                        isFirst?0: mLastId);
                });
                
                foreach (var dp in rv.Items)
                {
                    var x = new UIBiaoshi()
                    {
                        ID = dp.ID,
                        BangpaiType = dp.BangpaiType,
                        Name = dp.SiteUserName , 
                        XiakeName = dp.XiakeName,
                        XiakeId = dp.XiakeId,
                        CreateTime = dp.CreateTime, 
                        RegisterTime = dp.RegisterTime
                    };
                    this.Biaoshis.Add(x);
                }

                if (rv.Items.Count > 0)
                {
                    mLastId = rv.Items[rv.Items.Count - 1].ID;
                }
                mIsLoadedAllData = rv.IsLoadedAllData;
                if (isFirst)
                {
                    BiaoshiView.View.MoveCurrentToFirst();
                    TotalCount = rv.TotalCount;
                }
            }
            catch (Exception e)
            {
                e.Show();
            }
            finally
            {
                mIsSeaching = false;
                IsPageDataLoading = false;
            }

        }
 public BiaoshiMgmtViewModel()
 {
     //BindingOperations.EnableCollectionSynchronization(Servers,LockObject);
     Form = new SearchForm();
 }