c# - 获取json后数据绑定(bind)到listview

Question

我正在尝试了解 MVVM，并且很难让我的 ListView 显示可观察集合中的项目。我将 json 放入我设置的类中没有问题，但是让 xaml 读取绑定(bind)没有成功。我不太清楚如何设置它以便能够从 data2 读取属性。有人可以向我指出我做错了什么吗？

来自 reddit ，我需要获取每个Base.Data.Children.data.title。 0-24个 child ，所以我应该收到24个头衔。

型号

public class Child : BindableBase
{
    public string kind { get; set; }
    public Data2 data { get; set; }
}

public class Data2 : BindableBase
{
    public string title { get; set; }
}

public class Posts : ViewModelBase
{
    public string kind { get; set; }
    public Data data { get; set; }

    internal static Task<Posts> GetFileFromApplicationUriAsync(Uri uri)
    {
        throw new NotImplementedException();
    }
}

查看

         <ScrollViewer x:Name="PostsScrollViewer" HorizontalScrollBarVisibility="Hidden" 
                              Height="Auto" Width="Auto">
            <ListView x:Name="PostListBox" HorizontalContentAlignment="Stretch" ItemsSource="{Binding Children}" SelectedItem="{Binding Children}">
                <ListView.ItemTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding Children.Data.title}" />
                    </DataTemplate>
                </ListView.ItemTemplate>
            </ListView>

        </ScrollViewer>           

查看型号

View 模型库

 public abstract class ViewModelBase : INotifyPropertyChanged
{
    #region Property Changed Event Handler
    public void SetPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }
    public event PropertyChangedEventHandler PropertyChanged;
    #endregion Property Changed Event Handler
}

后 View 模型

    public class PostsViewModel : ViewModelBase
{
    private ObservableCollection<Child> children = new ObservableCollection<Child>();
    private ObservableCollection<Data2> data = new ObservableCollection<Data2>();
    private string title;

    #region Constructor
    public PostsViewModel()
    {
        GetFrontPagePostsAsync();
    }
    #endregion Constructor

    #region Properties
    #region Children
    public ObservableCollection<Child> Children
    {
        get { return this.children; }
        set
        {
            if (value != this.children)
                this.children = value;
            this.SetPropertyChanged("Children");
        }
    }
    #endregion Children
    #endregion Properties
    public async void GetFrontPagePostsAsync()
    {
        using (var client = new HttpClient())
        {
            try
            {
                string content = await client.GetStringAsync("http://www.reddit.com/.json");
                Posts posts = JsonConvert.DeserializeObject<Posts>(content);
                foreach (var i in posts.data.children)
                {
                    children.Add(i);
                }
            }
            catch (Exception e) {
                Console.WriteLine(e); }
        }
    }
}

Answer 1

首先，我假设您的 Children 收藏不是空的

然后，我认为您的问题出在 View 中。它应该是这样的:

查看

<ScrollViewer x:Name="PostsScrollViewer" HorizontalScrollBarVisibility="Hidden" 
                              Height="Auto" Width="Auto">
    <ListView x:Name="PostListBox" HorizontalContentAlignment="Stretch" ItemsSource="{Binding Children}" SelectedItem="{Binding Children}">
        <ListView.ItemTemplate>
            <DataTemplate>
                <TextBlock Text="{Binding Data.title}" />
            </DataTemplate>
        </ListView.ItemTemplate>
    </ListView>         
</ScrollViewer>           

改变的是 TextBlock 的行。
TextBlock (ListView) 的父级绑定(bind)到您的子级列表。这意味着 ListView 的每个 child 都“知道”它需要渲染的对象。在您的情况下，TextBlock 知道指定的子对象属性(取决于项目位置)。
如果您将页面绑定(bind)到某种 查看型号 ，您不需要将每个 child 绑定(bind)到

<TextBlock Text="{Binding ViewMode.Title}" />

但您只需将其绑定(bind)到:

<TextBlock Text="{Binding Title}" />