C # parse Json,

C # parse Json,

1. parse JSON data

Tool: Newtonsoft. Json class library/dll

Currently, I only use this class library to parse json data. This class library can be used to directly serialize and deserialize C # And JSON.

First, I copied a piece of json data written on the Internet in the local text file txt, such as (the path of the txt file is saved in disk D ):

Now, let's parse the json data in the txt text format! For a good demonstration, I will directly create a console Code as follows:

Using System; using System. collections. generic; using System. linq; using System. text; using System. threading. tasks; using Newtonsoft. json; using System. IO; using Newtonsoft. json. linq; namespace ConsoleApplication1 {class Program {static void Main (string [] args) {JsonSerializer serializer = new JsonSerializer (); using (StreamReader reader = new StreamReader (@ "d: \ json.txt ") using (JsonReader jsreader = new JsonTextReader (reader) {JObject jo = (JObject) serializer. deserialize (jsreader); // deserialization of json is then converted to JObject Console. writeLine (jo. toString ();} Console. read ();}}}

Running result:

2. Linq To Json

Main classes of linq to json:

1. JObejct: json object

2. JArray: used to operate json Arrays

3. JValue: Value in the array

4. JProperty: The property of a json object, which usually exists in a dictionary similar to a key or value.

5. JToken: used to store the result value of the linq Query

The following example shows how to use JObejct to create json data and output the following code:

Using System; using System. collections. generic; using System. linq; using System. text; using System. threading. tasks; using Newtonsoft. json; using System. IO; using Newtonsoft. json. linq; namespace ConsoleApplication1 {class Program {static void Main (string [] args) {JObject jo = new JObject (); jo. add (new JProperty ("name", "Zhang huimei"); jo. add (new JProperty ("sex", "female"); jo. add (new JProperty ("age", "32"); jo. add (new JProperty ("teachar", new JObject (new JProperty ("name", "Zhang Yusheng"), new JProperty ("sex", "male "), new JProperty ("age", "30"); Console. writeLine (jo. toString (); Console. readLine ();}}}

On this basis, modify the code:

Using System; using System. collections. generic; using System. linq; using System. text; using System. threading. tasks; using Newtonsoft. json; using System. IO; using Newtonsoft. json. linq; namespace ConsoleApplication1 {class Program {static void Main (string [] args) {JObject jo = new JObject (); jo. add (new JProperty ("name", "Zhang huimei"); jo. add (new JProperty ("sex", "female"); jo. add (new JProperty ("age", "32"); jo. add (new JProperty ("teachar", new JObject (new JProperty ("name", "Zhang Yusheng"), new JProperty ("sex", "male "), new JProperty ("age", "30"); JToken Tteacher = jo ["teachar"]; Console. writeLine (Tteacher. toString (); Console. readLine ();}}}

From this we can know that the value returned by the JToken is actually the value part of the corresponding key. Then we can use linq to json to prepare a string and use linq to query the name of Wang Lihong's friend:

Using System; using System. collections. generic; using System. linq; using System. text; using System. threading. tasks; using Newtonsoft. json; using System. IO; using Newtonsoft. json. linq; namespace ConsoleApplication1 {class Program {static void Main (string [] args) {string jsonstr = "{\" Name \ ": \" Wang Li Hong \", \ "Age \": 34, \ "friends \": [{\ "Name \": \ "Lin Junjie \", \ "Age \": 30 }, {\ "Name \": \ "Zhang huimei \", \ "Age \": 29}]} "; JObject jo = JObject. parse (jsonstr); var a = from B in jo ["friends"]. children () select (string) B ["Name"]; foreach (var item in a) {Console. writeLine (item);} Console. read ();}}}

Here is a simple introduction to Json parsing... Please correct me if there is anything wrong or you need to correct it.