WinRT知识积累2之MessageDialog应用代码

private void NavigationHelper_SaveState(object sender, SaveStateEventArgs e)
        {
            // TODO: 在此处保存页面的唯一状态。
            ApplicationDataContainer localsetting = Windows.Storage.ApplicationData.Current.LocalSettings;
            if ((String)localsetting.Values["AppCourt"] == "2")
            {
                localsetting.Values["AppCourt"] = "3";
                showMessageBox();
            }
            else if (localsetting.Values.ContainsKey("AppCourt"))
            {
                localsetting.Values["AppCourt"] =(int.Parse((String)localsetting.Values["AppCourt"])+1).ToString();
            }
            else
            {
                localsetting.Values["AppCourt"] = "1";
            }
        }
        async void  showMessageBox()
        {
            MessageDialog messagedialog = new MessageDialog("给个好评鼓励开发=_=");
            messagedialog.Commands.Add(new UICommand("好评",new UICommandInvokedHandler(this.CommandRateInvokedHandler)));
            messagedialog.Commands.Add(new UICommand("取消"));
            await messagedialog.ShowAsync();
        }