使用不良连接时Xamarin应用突然崩溃

问题描述

当我的应用遇到连接问题时，它突然崩溃并且没有引发异常。我已经放了Microsoft App Center插件，这是当机报告：

Xamarin Exception Stack:
System.NullReferenceException: Object reference not set to an instance of an object
  at Project.XAML.AtendimentosUser.GetData (System.Collections.Specialized.NameValueCollection data) [0x000f3] in <8ee15104665a463180bbffb742ed9570>:0
  at System.Runtime.CompilerServices.AsyncmethodBuilderCore+<>c.<ThrowAsync>b__7_0 (System.Object state) [0x00000] in <0db975f2d36842718f4da4da36d2fcb7>:0
  at Android.App.SyncContext+<>c__displayClass2_0.<Post>b__0 () [0x00000] in <c2957c7ec1ac46f688b7f30f24232572>:0
  at java.lang.Thread+RunnableImplementor.Run () [0x00008] in <c2957c7ec1ac46f688b7f30f24232572>:0
  at java.lang.IRunnableInvoker.n_Run (system.intPtr jnienv,system.intPtr native__this) [0x00008] in <c2957c7ec1ac46f688b7f30f24232572>:0
  at (wrapper dynamic-method) Android.Runtime.DynamicmethodNameCounter.35(intptr,intptr)

AtendimentosUser.GetData方法的代码：

async void GetData(NameValueCollection data)
{
    /* try {  */
    
        StackListagem.IsVisible = false;
        SemResultados.IsVisible = false;
        LoadingItems.IsRunning = true;
        LoadingContainer.IsVisible = true;

        WebService client = new WebService();
        agendamentos = await Task.Run(() => client.PostData<List<Agendamento>>(url,data,debug: true));

        LoadingContainer.IsVisible = false;
        LoadingItems.IsRunning = false;

        if (agendamentos.Count > 0)
        {
            LabelListagem.Text = "Você tem " + agendamentos.Count + " agendamento(s) para " + ((Mes)PickerMes.SelectedItem).label + " de " + PickerAno.SelectedItem;
            ListagemAgendamento.ItemsSource = agendamentos;
            StackListagem.IsVisible = true;
        }
        else
        {
            CaptionTxt.Text = "Você não possui agendamentos" + Environment.NewLine + " para " + ((Mes)PickerMes.SelectedItem).label + " de " + PickerAno.SelectedItem;
            SemResultados.IsVisible = true;
        }
    
    /* } catch  { GetData(data); } */
}

我刚刚添加了try / catch，但是我不知道这样是否可以正确处理问题。

你们看到导致此问题的原因了吗？

解决方法

暂无找到可以解决该程序问题的有效方法，小编努力寻找整理中！

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