Question

我有这个GridView

       <GridView ItemsSource="{x:Bind myInspectedList}" 
              Grid.Row="1"
              Name="dashboard_gridview"
                  HorizontalAlignment="Center"

             >
        <GridView.ItemTemplate>
            <DataTemplate x:DataType="data:TrucksModel">
                <StackPanel 
                    Margin="50,20,50,20"
                    Orientation="Vertical"
                    HorizontalAlignment="Center"
                    >
                    <TextBlock 
                        Text="{x:Bind driver_name}"
                        Margin="20,10,0,0"
                        FontSize="80" 
                        />
                    <TextBlock >Testing val</TextBlock>

                </StackPanel>
            </DataTemplate>

        </GridView.ItemTemplate>

    </GridView>

现在在我的c＃代码中加载网格数据但无法在异步请求中加载数据。请求是一个php Web服务因此需要使它成为异步请求

  private List<TrucksModel> myInspectedList;

        public async Task<InspectionDashboardPage> InitializeAsync() //async constructor
    {
        Debug.WriteLine("Called async method");
        List<TrucksModel> fetchedlists = new List<TrucksModel>();
        try
        {
            var response = await helpers.InspectionHttp.GetMyInspections();
            var result = await response.Content.ReadAsStringAsync();
           TrucksModel dashboardhttpres = JsonConvert.DeserializeObject<TrucksModel>(result);

           myInspectedList = dashboardhttpres ;
           dashboard_gridview.UpdateLayout();  //doesnt update items

             Debug.WriteLine("Total items are "+myInspectedList.Count);  //this returns 10 records
        }
        catch (Exception exp)
        {
         myInspectedList = fetchedlists;  //make it empty
            Debug.WriteLine(exp.Message);
        }

        return this;
    }

如何在async请求返回数据时更新sysnc请求中的网格，但网格永远不会更新

Answer 1

如果您正确完成了绑定，则无需担心异步。我在WPF中做过一次REST api测试，它没有任何投诉或错误。以下是我的项目中的示例：

public class ProjectViewModel : BaseViewModel
{
    private string result;
    public string Result { get { return result; } set { result = value; NotifyPropertyChanged(); } }

private void SendMessage()
{
    {
        Task.Run(async delegate
        {
            try
            {
                HttpContent content = new StringContent("");
                content = new StringContent(SelectedRestMessage.Message);
                content.Headers.ContentType = new MediaTypeHeaderValue(SelectedRestMessage.MessageType);
                Result = await client.PostAsync(SelectedRestMessage.Adres, content).Result.Content.ReadAsStringAsync();        
            }
            catch (Exception e)
            {
                Result = "Oeps Something went wrong";
            }
        });
    }
}

我删除了一些令人分心的代码，因此更容易阅读。

C＃Uwp绑定GridViewTo异步数据

1 个答案: