c#-4.0 - windows phone 中的列表框加载问题

Question

我在 XAML 中有一个列表框，我正在用这个 litbox 输入一些数据。如下所示

 lstsumitedreport = new ObservableCollection<ClsGetSubmittedReport>();             
            if (ResultCode == "1")
            {

                JArray arry = (JArray)obj["GetSubmittedReportComment"];
                if (arry != null)
                {
                    total = arry.Count;
                    for (int i = 0; i < arry.Count; i++)
                    {

                        JObject obj1 = (JObject)arry[i];
                        int reportId = (int)obj1["ReportId"];
                        string positiveCmnt = (string)obj1["PositiveComment"];
                        string NagativeCmnt = (string)obj1["negativecomment"];
                        DateTime dt = (DateTime)obj1["TimeStamp"];
                        string time = (string)obj1["TimeStampString"];
                        DateTime dtlocal = DateTime.ParseExact(time, "yyyy/MM/dd HH:mm:ss", CultureInfo.InvariantCulture);                        
                        string timestamp = dtlocal.ToString("MM/dd/yyyy hh:mm tt", CultureInfo.InvariantCulture);


                        lstsumitedreport.Add(new ClsGetSubmittedReport(reportId, positiveCmnt, NagativeCmnt, timestamp, Csi, goodimagepath, bedimagepath, goodimgline, bedimgline, font, PHeight, NHeight));

                    }
                }                                           
                TransactionList.ItemsSource = null;
                this.TransactionList.ItemsSource = lstsumitedreport;
                tbOutstandingCount.Text = total.ToString();                            
            }

这里的横断列表是我的列表框名称。调试波纹管后，显示数据需要很长时间。

 this.TransactionList.ItemsSource = lstsumitedreport;

我该如何解决这个问题