Windows Store App 中挂起时，程序奔溃的问题

System.Runtime.InteropServices.COMException (0x80004005): Unspecified error

GetNavigationState doesn‘t support serialization of a parameter type which was passed to Frame.Navigate.
   at Windows.UI.Xaml.Controls.Frame.GetNavigationState()
   at TX.WifiSurfing.Common.SuspensionManager.SaveFrameNavigationState(Frame frame)
   at TX.WifiSurfing.Common.SuspensionManager.<SaveAsync>d__0.MoveNext()
System.Collections.ListDictionaryInternal

       /// <summary>
        /// 在将要挂起应用程序执行时调用。    将保存应用程序状态
        /// 将被终止还是恢复的情况下保存应用程序状态，
        /// 并让内存内容保持不变。
        /// </summary>
        private async void OnSuspending(object sender, SuspendingEventArgs e)
        {
            var deferral = e.SuspendingOperation.GetDeferral();
            await SuspensionManager.SaveAsync();
            deferral.Complete();
        }