HubSection

Question

当我点击listview上的任何项目时，我收到此错误。 System.NullReferenceException - {“对象引用未设置为对象的实例。”}

我的MainPage.xaml中心代码

<Hub x:Name="MainHub" Header="My Hub">
<HubSection x:Name="Test" Header="Online" Visibility="Collapsed" Margin="0,30,0,0">
<DataTemplate>
<ListView Name="ItemData1"  ItemsSource="{Binding}" SelectionChanged="Catergory_Click">
 <ListView.ItemContainerStyle>
 <Style TargetType="ListViewItem">
 <Setter Property="HorizontalContentAlignment" Value="Stretch" />
 <Setter Property="FontSize" Value="18"/>
 </Style>
 </ListView.ItemContainerStyle>
 </ListView>
 </DataTemplate>
 </HubSection>
 </Hub>

我有3个具有相同SelectionChanged功能的ListView

MainPage.xaml.cs中

public class RootObject
    {
        public int id { get; set; }
        public string name { get; set; }
        public string message { get; set; }
    }

 private void Catergory_Click(object sender, SelectionChangedEventArgs e)
    {

        RootObject obj = (sender as ListView).SelectedItem as RootObject;
        User.Setting.AddOrUpdateValue("SectionName", obj.name);

    }

相同的代码在没有Hub控件和Section的情况下工作正常。

Answer 1

立即将SelectionChanged更改为ItemClick..Works

 <Hub x:Name="MainHub" Header="My Hub" Foreground="White">       
<HubSection x:Name="Test" Header="Online" Visibility="Collapsed" Margin="0,30,0,0">
    <DataTemplate>
        <ListView x:Name="TestListView" ItemsSource="{Binding}" ItemClick="TestListView_ItemClick" IsItemClickEnabled="True" >
            <ListView.ItemTemplate>
                <DataTemplate>
                    <TextBlock x:Name="textBlock"  Text="{Binding name}"/>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>
    </DataTemplate>
</HubSection>

private void TestListView_ItemClickobject sender, ItemClickEventArgs e)
    {
        RootObject obj = e.ClickedItem as RootObject;
        User.Setting.AddOrUpdateValue("CourseSectionName", obj.name); 
    }