DataBinding反序列化的json数组

Question

我对C＃，silverlight和整个数据绑定范例都比较陌生。我一直在研究一个小测试应用程序，它使用Json.Net通过API从reddit获取数据。无论如何，我将数据输入到我的应用程序中就好了，但现在我无法将数据推送到用户界面。我尝试了几种不同的配置无济于事。无论如何，代码是在这里：

public partial class MainPage : PhoneApplicationPage 
{ 
    string json = ""; 
    RootObject topic { get; set; } 
    public MainPage() 
    { 
     InitializeComponent(); 
    } 
    private void button1_Click(object sender, RoutedEventArgs e) 
    { 
     textBlock1.Text = "Retrieving..."; 
     string url = @"http://www.reddit.com/r/all.json"; 
     HttpWebRequest hWebRequest = (HttpWebRequest)HttpWebRequest.Create(url); 
     hWebRequest.Method = "GET"; 
     hWebRequest.BeginGetResponse(Response_Completed, hWebRequest); 
    } 
    public void Response_Completed(IAsyncResult result) 
    { 
     HttpWebRequest request = (HttpWebRequest)result.AsyncState; 
     HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(result); 
     using (StreamReader streamReader = new StreamReader(response.GetResponseStream())) 
     { 
      json = streamReader.ReadToEnd(); 
      topic = JsonConvert.DeserializeObject<RootObject>(json); 
     } 
     Deployment.Current.Dispatcher.BeginInvoke(() => 
     { 
      this.DataContext = topic.data.children[0].data.title; 
      textBlock1.Text = "Done."; 
     }); 
    } 

这是我的代码的主要部分。其余的类都在这里，它们用于反编译API提供的JSON的反序列化。

public class MediaEmbed 
    { 
     public string content { get; set; } 
     public int? width { get; set; } 
     public bool? scrolling { get; set; } 
     public int? height { get; set; } 
    } 
    public class Oembed 
    { 
     public string provider_url { get; set; } 
     public string description { get; set; } 
     public string title { get; set; } 
     public string url { get; set; } 
     public string author_name { get; set; } 
     public int height { get; set; } 
     public int width { get; set; } 
     public string html { get; set; } 
     public int thumbnail_width { get; set; } 
     public string version { get; set; } 
     public string provider_name { get; set; } 
     public string thumbnail_url { get; set; } 
     public string type { get; set; } 
     public int thumbnail_height { get; set; } 
     public string author_url { get; set; } 
    } 
    public class Media 
    { 
     public string type { get; set; } 
     public Oembed oembed { get; set; } 
    } 
    public class Data2 
    { 
     public string domain { get; set; } 
     public MediaEmbed media_embed { get; set; } 
     public object levenshtein { get; set; } 
     public string subreddit { get; set; } 
     public string selftext_html { get; set; } 
     public string selftext { get; set; } 
     public object likes { get; set; } 
     public bool saved { get; set; } 
     public string id { get; set; } 
     public bool clicked { get; set; } 
     public string title { get; set; } 
     public Media media { get; set; } 
     public int score { get; set; } 
     public bool over_18 { get; set; } 
     public bool hidden { get; set; } 
     public string thumbnail { get; set; } 
     public string subreddit_id { get; set; } 
     public string author_flair_css_class { get; set; } 
     public int downs { get; set; } 
     public bool is_self { get; set; } 
     public string permalink { get; set; } 
     public string name { get; set; } 
     public double created { get; set; } 
     public string url { get; set; } 
     public string author_flair_text { get; set; } 
     public string author { get; set; } 
     public double created_utc { get; set; } 
     public int num_comments { get; set; } 
     public int ups { get; set; } 
    } 
    public class Child 
    { 
     public string kind { get; set; } 
     public Data2 data { get; set; } 
    } 
    public class Data 
    { 
     public string modhash { get; set; } 
     public Child[] children { get; set; } 
     public string after { get; set; } 
     public object before { get; set; } 
    } 
    public class RootObject 
    { 
     public string kind { get; set; } 
     public Data data { get; set; } 
    }  
} 

假设的XAML UI的东西看起来像这样

  <ListBox> 
      <ListBox.ItemTemplate> 
       <DataTemplate> 
        <StackPanel> 
         <TextBlock x:Name="TitleInfo" /> 
         <TextBlock x:Name="AuthorInfo" /> 
        </StackPanel> 
       </DataTemplate> 
      </ListBox.ItemTemplate> 
     </ListBox> 

的标题包含RootObject实例的内部调用话题。因此，要抢冠军的方式是

topic.data.children[0].data.title; 

不过，我几乎没有任何想法我怎么能结合，对这些文本框或listbox..I知道一个DataContext必须设置这些项目可以绑定通过代码，而不是XAML，但我无法找出任何优雅的方式来做到这一点。任何帮助？万分感谢。

Answer 1

从外表看，你几乎就在那里。你的问题是，你试图将整个页面的DataContext设置为一个记录中的单个标题（this.DataContext = topic.data.children[0].data.title;） - 这可能不是你的意思...

要将数据放入ListBox，你有2个选择 - 你可以明确地像这样

myListBox.ItemsSource = topic.data.children; 

设置的ItemsSource列表框，然后更新XAML显示来自对象图中该点的数据...

<ListBox Name="MyListBox"> 
    <ListBox.ItemTemplate> 
     <DataTemplate> 
      <StackPanel> 
       <TextBlock x:Name="TitleInfo" Text="{Binding data.title}" /> 
       <TextBlock x:Name="AuthorInfo" Text="{Binding data.author}" /> 
      </StackPanel> 
     </DataTemplate> 
    </ListBox.ItemTemplate> 
</ListBox> 

然而，如果你正在寻找在t中的其他地方使用数据他的页面，你可能会想要为整个页面设置DataContext。

DataContext = topic; 

和你的列表框XAML设置的东西稍微不同......

<ListBox Name="MyListBox" ItemsSource="{Binding data.children}" > 
    <ListBox.ItemTemplate> 
     <DataTemplate> 
      <StackPanel> 
       <TextBlock x:Name="TitleInfo" Text="{Binding data.title}" /> 
       <TextBlock x:Name="AuthorInfo" Text="{Binding data.author}" /> 
      </StackPanel> 
     </DataTemplate> 
    </ListBox.ItemTemplate> 
</ListBox> 

希望这有助于。

Answer 2

如果要处理DataBinidng，最好实施MVVM模式。

在此期间，这里就是你们的榜样的修复：

public partial class MainPage : PhoneApplicationPage, INotifyPropertyChanged 
{ 
    string json = ""; 
    private RootObject topic; 

    public event PropertyChangedEventHandler PropertyChanged; 

    public RootObject Topic 
    { 
     get 
     { 
      return this.topic; 
     } 
     set 
     { 
      this.topic = value; 
      var handler = this.PropertyChanged; 
      if (handler != null) 
      { 
       handler(this, new PropertyChangedEventArgs("Topic")); 
      } 
     } 
    } 

    public MainPage() 
    { 
     InitializeComponent(); 
     this.DataContext = this; 
    } 
    private void button1_Click(object sender, RoutedEventArgs e) 
    { 
     ... 
    } 
    public void Response_Completed(IAsyncResult result) 
    { 
     HttpWebRequest request = (HttpWebRequest)result.AsyncState; 
     HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(result); 
     using (StreamReader streamReader = new StreamReader(response.GetResponseStream())) 
     { 
      json = streamReader.ReadToEnd(); 
      this.Topic = JsonConvert.DeserializeObject<RootObject>(json); 
     } 
    } 
} 

和更新的XAML：

<ListBox Name="MyListBox" ItemsSource="{Binding Topic.data.children}" > 
    <ListBox.ItemTemplate> 
     <DataTemplate> 
      <StackPanel> 
       <TextBlock x:Name="TitleInfo" Text="{Binding data.title}" /> 
       <TextBlock x:Name="AuthorInfo" Text="{Binding data.author}" /> 
      </StackPanel> 
     </DataTemplate> 
    </ListBox.ItemTemplate> 
</ListBox>