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The introduction

Json is a data transfer format that we often use in our work, and parsing JSON is a common problem in the beginning. NewtonsoftJson is a set of json processing encapsulation classes for c#, which can help us efficiently and easily handle json.

NetonSoftJson provides the complete usage Documentation at Json.NET Documentation

Different usage scenarios of NetonSoftJson

Common methods serialization and deserialization

These are probably the two things we use the most

JsonConvert. DeserializeObject < T > (string json) / / deserialization JsonConvert. SerializeObject (object obj) / / serializationCopy the code

Advanced features

See the article newtonsoft.json for advanced usage

Some fields do not want to be deserialized

Use the JsonIgnore feature tag

public class Person { public int Age { get; set; } public string Name { get; set; } [JsonIgnore] public string Sex { get; set; }}Copy the code

Custom serialization name

public class Person { public int Age { get; set; } public string Name { get; set; } [JsonProperty(PropertyName = "SepcialSex")] public string Sex { get; set; }}Copy the code

Parse literal strings

First build a JSON object, describing a teacher’s entity, which contains the basic attributes of the teacher (name, age), the attributes of the managed class, the managed class student array

{" name ":" zhang ", "age" : "10", "classroom" : {" name ":" class 1, grade 1 ", "desc" : "describe"}, "students" : [{" age ":" nickname "}, {" age ": "Little red"}]}Copy the code

Next we use Newtonsoftjson to parse the string and get the information we need

string jsonStr = "{\" name \ ": \" zhang SAN \ ", \ "age \" : \ "10 \", \ "classroom \" : {\ "name \" : \ "class 1, grade 1 \", \ "desc \" : \ \ "described"}, \ "students \" : [{\ "name \" : \ "name \"}, {\ "n Ame \ ", \ "little red \}]"} "; JObject jObject = JObject.Parse(jsonStr);Copy the code

Get name

Console.WriteLine("name is " + jObject["name"].ToString());
Console.WriteLine("age is " + jObject.GetValue("age").ToString());
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Get class information

Console.WriteLine("classroom name is " + jObject["classroom"]["name"]);
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Access to student information

JArray jArray = JArray.Parse(jObject["students"].ToString());
foreach (var arr in jArray)
{
    JObject jObj = JObject.Parse(arr.ToString());
    string name = jObj["name"].ToString();
    Console.WriteLine("student name  is " + name);
}
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Check whether the key exists

// Key does not exist if (jobject. Property(" ABC ")! = null) { Console.WriteLine(jObject.Property("abc").Value.ToString()); } else {console. WriteLine(" Current key does not exist "); }Copy the code

Application under WebApi

Nullable<> = Nullable<> = Nullable<> = int? , a DateTime? , the value returned by the null value field serialization is null, the foreground corresponding field assignment needs to perform null value judgment, how to replace null globally.

.NET Core handles WebAPI JSON and returns an annoying null null

conclusion

The use of Json is far more than that. The author just sorted out the common problems in his work so far, and will gradually add new content in the future, and constantly update and optimize the article.

The END

The end of this article, I hope to help you 😃

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