Detailed description of ASP. NET's method for extracting multi-layer nested json data, asp. netjson

Detailed description of ASP. NET's method for extracting multi-layer nested json data, asp. netjson

This example describes how ASP. NET uses the third-party class library Newtonsoft. Json to extract multi-layer nested json data. The example is as follows.

Assume that the json string to be extracted is as follows:

{"name":"lily","age":23,"addr":{"city":guangzhou,"province":guangdong}}

Reference namespace first:

using Newtonsoft.Json;using Newtonsoft.Json.Linq;

You can regard the preceding json string as an object, as long as you write the corresponding class (if you use VS2013 for development, you can quickly convert a JSON string to an object class by editing, selecting, and pasting json as a class)

 public class UserInfo {  public string name;  public int age;  public address addr; } public class address {  public string city;  public string province; }

1. The code for converting a json string to an object is as follows:

string jsonData="{\"name\":\"lily\",\"age\":23,\"addr\":{\"city\":guangzhou,\"province\":guangdong}}";UserInfo user=(UserInfo)JsonConvert.DeserializeObject(jsonData, typeof(UserInfo));

2. You can use the following code to read the value of an attribute in json:

JObject jsonObj = JObject.Parse(jsonData);string name=jsonObj ["name"].ToString();string age=jsonObj ["age"].ToString();string city=((JObject )jsonObj ["addr"])["city"].ToString();string province=((JObject )jsonObj ["addr"])["province"].ToString();

3. interpret multi-layer nested json to obtain the value of any attribute:

If the json string to be processed is as follows:

{"name":"lily","age":23,"addr":{"city":guangzhou,"province":guangdong}};

Then let you input an object, such as "city", the system will output "guangzhou", input "age", and output "23 ". Json is multi-level nested and needs to be traversed one by one. The Code is as follows:

  public string GetJsonValue(JEnumerable<JToken> jToken, string key)  {   IEnumerator enumerator = jToken.GetEnumerator();   while (enumerator.MoveNext())   {    JToken jc = (JToken)enumerator.Current;    if (jc is JObject || ((JProperty)jc).Value is JObject)    {     return GetJsonValue(jc.Children(), key);    }    else    {     if (((JProperty)jc).Name == key)     {      return ((JProperty)jc).Value.ToString();     }    }   }   return null;  }

Code for calling GetJsonValue:

string jsonData = "{\"name\":\"lily\",\"age\":23,\"addr\":{\"city\":\"guangzhou\",\"province\":\"guangdong\"}}";JObject jsonObj = JObject.Parse(jsonData);Response.Write(GetJsonValue(jsonObj.Children(), "province"));

You can also use the following code for multi-layer nested Arrays:

string jsonData = "{\"addr\":[{\"city\":\"guangzhou\",\"province\":\"guangdong\"},{\"city\":\"guiyang\",\"province\":\"guizhou\"}]}";JObject jsonObj = JObject.Parse(jsonData);JArray jar = JArray.Parse(jsonObj["addr"].ToString());JObject j = JObject.Parse(jar[0].ToString());Response.Write(j["city"]);

4. Convert JSON to XML:

Copy codeThe Code is as follows:
String xmlstr = (XmlDocument) JsonConvert. DeserializeXmlNode (jsonData). InnerXml. ToString ();

The above is all the content of this article. I hope it will be helpful for your learning and support for helping customers.