c# - 在 C# 中迭代​​ JSON 对象

Question

我在 C# 中使用 JSON.NET 来解析来自 Klout API 的响应。我的回复是这样的：

[
  {
    "id": "5241585099662481339",
    "displayName": "Music",
    "name": "music",
    "slug": "music",
    "imageUrl": "http://kcdn3.klout.com/static/images/music-1333561300502.png"
  },
  {
    "id": "6953585193220490118",
    "displayName": "Celebrities",
    "name": "celebrities",
    "slug": "celebrities",
    "imageUrl": "http://kcdn3.klout.com/static/images/topics/celebrities_b32741b6703151cc7bd85fba24c44c52.png"
  },
  {
    "id": "5757029936226020304",
    "displayName": "Entertainment",
    "name": "entertainment",
    "slug": "entertainment",
    "imageUrl": "http://kcdn3.klout.com/static/images/topics/Entertainment_7002e5d2316e85a2ff004fafa017ff44.png"
  },
  {
    "id": "3718",
    "displayName": "Saturday Night Live",
    "name": "saturday night live",
    "slug": "saturday-night-live",
    "imageUrl": "http://kcdn3.klout.com/static/images/icons/generic-topic.png"
  },
  {
    "id": "8113008320053776960",
    "displayName": "Hollywood",
    "name": "hollywood",
    "slug": "hollywood",
    "imageUrl": "http://kcdn3.klout.com/static/images/topics/hollywood_9eccd1f7f83f067cb9aa2b491cd461f3.png"
  }
]

如您所见，它包含 5 个id标签。也许下次它会是 6 或 1 或其他数字。我想遍历 JSON 并获取每个id标签的值。在不知道会有多少的情况下，我无法运行循环。我该如何解决这个问题？

Answer 1

dynamic dynJson = JsonConvert.DeserializeObject(json);
foreach (var item in dynJson)
{
    Console.WriteLine("{0} {1} {2} {3}\n", item.id, item.displayName, 
        item.slug, item.imageUrl);
}

或者

var list = JsonConvert.DeserializeObject<List<MyItem>>(json);

public class MyItem
{
    public string id;
    public string displayName;
    public string name;
    public string slug;
    public string imageUrl;
}

Answer 2

您可以使用JsonTextReader来读取 JSON 并遍历令牌：

using (var reader = new JsonTextReader(new StringReader(jsonText)))
{
    while (reader.Read())
    {
        Console.WriteLine("{0} - {1} - {2}", 
                          reader.TokenType, reader.ValueType, reader.Value);
    }
}

Answer 3

这对我有用，将嵌套 JSON 转换为易于阅读的 YAML

    string JSONDeserialized {get; set;}
    public int indentLevel;

    private bool JSONDictionarytoYAML(Dictionary<string, object> dict)
    {
        bool bSuccess = false;
        indentLevel++;

        foreach (string strKey in dict.Keys)
        {
            string strOutput = "".PadLeft(indentLevel * 3) + strKey + ":";
            JSONDeserialized+="\r\n" + strOutput;

            object o = dict[strKey];
            if (o is Dictionary<string, object>)
            {
                JSONDictionarytoYAML((Dictionary<string, object>)o);
            }
            else if (o is ArrayList)
            {
                foreach (object oChild in ((ArrayList)o))
                {
                    if (oChild is string)
                    {
                        strOutput = ((string)oChild);
                        JSONDeserialized += strOutput + ",";
                    }
                    else if (oChild is Dictionary<string, object>)
                    {
                        JSONDictionarytoYAML((Dictionary<string, object>)oChild);
                        JSONDeserialized += "\r\n";  
                    }
                }
            }
            else
            {
                strOutput = o.ToString();
                JSONDeserialized += strOutput;
            }
        }

        indentLevel--;

        return bSuccess;

    }

用法

        Dictionary<string, object> JSONDic = new Dictionary<string, object>();
        JavaScriptSerializer js = new JavaScriptSerializer();

          try {

            JSONDic = js.Deserialize<Dictionary<string, object>>(inString);
            JSONDeserialized = "";

            indentLevel = 0;
            DisplayDictionary(JSONDic); 

            return JSONDeserialized;

        }
        catch (Exception)
        {
            return "Could not parse input JSON string";
        }