C＃解析JSON數組元素

Question

我正在開發VS 2012中的Windows 8商店應用程序，並且新增了C＃和XAML。使用JsonArray解析Json訂閱源如何從另一個數組中的數組中獲取元素？

[ 

    { 
     "item_id": 2270978, 
     "item_title": "This is the title", 
     "roles": [ 

      { 
       "item_url": "http://www.blahblah.com/161089", 
       "parent_url": "http://www.blahblah.com", 
      }, 
      { 
       "item_url": "http://www.blahblah.com/469888", 
       "parent_url": "http://www.blahblah.com", 
      } 

     ], 
    } 
] 

我想另一個的foreach將原來的foreach內工作，但我得到一個錯誤：

Cannot apply indexing with [] to an expression of type 'Windows.Data.Json.IJsonValue'

  foreach (var item in items) 
      { 
       JsonObject theItem = item.GetObject(); 
       FeedItem feedItem = new FeedItem(); 

       feedItem.PubDate = System.DateTime.Now; 
       feedItem.Title = theItem["item_title"].GetString(); 
       feedItem.Author = "Me"; 
       feedItem.ItemId = (int)(theItem["item_id"].GetNumber()); 
       feedItem.Content = theItem["item_body"].GetString(); 
       feedItem.Link = new Uri(theItem["permalink_url"].GetString()); 

       var roles = theItem["roles"].GetArray(); 
/* TRIED LIKE THIS DOESN'T WORK 
       foreach (var role in roles) 
       { 
        feedItem.ContentUrl = new Uri(role["item_url"].GetString()); 
       } 
*/ 
       feed.Items.Add(feedItem); 
      } 

Answer 1

你遍歷錯誤的變量。應該是：

  var roles = theItem["roles"].GetArray(); 
      foreach (var role in roles) 
      { 
       feedItem.ContentUrl = new Uri(role.GetObject()["item_url"].GetString()); 
      } 

此外，在您的輸入JSON字符串中沒有content_url元素。它不應該是item_url或parent_url？