尝试在Win Mobile 8 c#中保存数据时出现未处理的异常

我正在使用下面的代码尝试使用c#保存到Windows Mobile 8中的本地设置。

 public void SaveInfo(string key, string value)
        {
            if (ApplicationData.Current.LocalSettings.Values.ContainsKey(key))
            {
                if (ApplicationData.Current.LocalSettings.Values[key].ToString() != null)
                {
                    // do update
                    ApplicationData.Current.LocalSettings.Values[key] = value;
                }
            }
            else
            {
                // do create key and save value, first time only.
                ApplicationData.Current.LocalSettings.CreateContainer(key, ApplicationDataCreateDisposition.Always);
                if (ApplicationData.Current.LocalSettings.Values[key] == null)
                {
                    ApplicationData.Current.LocalSettings.Values[key] = value;
                }
            }
        }

调用代码时，调试崩溃，出现以下异常：

类型的未处理异常中出现"System.Reflection.TargetInvocationException"System.Windows.ni.dll

任何想法

IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;

            settings["test"] = urlText.Text;
            settings.Save();