Asp.net JSON serialization and deserialization instructions

In. net JSON serialization and deserialization, we can use the DataContractJsonSerializer class to serialize type instances. I will introduce them in detail.

Serialize and deserialize JSON data

You can use the DataContractJsonSerializer class to serialize a type instance to a JSON string and deserialize the JSON string to a type instance. DataContractJsonSerializer in System. runtime. serialization. in the Json namespace ,. NET Framework 3.5 is included in System. serviceModel. web. dll, you need to add a reference to it ;. NET Framework 4 in the System. runtime. serialization.

Method 1: introduce the System. Web. Script. Serialization namespace and use the JavaScriptSerializer class to implement simple Serialization class: Personnel

 

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Public class Personnel { Public int Id {get; set ;} Public string Name {get; set ;} }

Execute serialization deserialization:

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Protected void Page_Load (object sender, EventArgs e) { Personnel personnel = new Personnel (); Personnel. Id = 1; Personnel. Name = ""; JavaScriptSerializer jsonSerializer = new JavaScriptSerializer (); // Execute serialization String r1 = jsonSerializer. Serialize (personnel ); // Execute deserialization Personnel _ Personnel = jsonSerializer. Deserialize <Personnel> (r1 ); }

R1 output result: {"Id": 1, "Name": ""}
You can use the ScriptIgnore attribute to mark public or public fields that are not serialized.

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Public class Personnel { [ScriptIgnore] Public int Id {get; set ;} Public string Name {get; set ;} }

R1 output result: {"Name": ""}

Method 2: introduce the System. Runtime. Serialization. Json namespace and use the DataContractJsonSerializer class for Serialization.

Serialization class: People

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Public class People { Public int Id {get; set ;} Public string Name {get; set ;} }

Execute serialization deserialization

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Protected void Page_Load (object sender, EventArgs e) { People people = new People (); People. Id = 1; People. Name = ""; DataContractJsonSerializer json = new DataContractJsonSerializer (people. GetType ()); String szJson = ""; // Serialization Using (MemoryStream stream = new MemoryStream ()) { Json. WriteObject (stream, people ); SzJson = Encoding. UTF8.GetString (stream. ToArray ()); } // Deserialization Using (MemoryStream MS = new MemoryStream (Encoding. UTF8.GetBytes (szJson ))) { DataContractJsonSerializer serializer = new DataContractJsonSerializer (typeof (People )); People _ people = (People) serializer. ReadObject (MS ); } }

SzJson output result: {"Id": 1, "Name": ""}

You can use IgnoreDataMember to specify that the member is not part of the Data Protocol and is not serialized. DataMember: defines the serialization attribute parameters. Fields marked with the DataMember attribute must use the DataContract tag class. Otherwise, the DataMember tag does not work.

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[DataContract] Public class People { [DataMember (Name = "id")] Public int Id {get; set ;} [IgnoreDataMember] Public string Name {get; set ;} }

Output result: {"id": 1}

Processing of JSON serialization and deserialization Date and Time
JSON format does not support date and time. The DateTime value is displayed as a JSON string in the format of "/Date (700000 + 0500)/", where the first number (700000 In the example provided) it is the number of milliseconds that have elapsed since midnight, January 1, January 1, 1970 by normal time (non-timeout. This number can be a negative number to indicate the previous time. The example contains "+ 0500", which indicates that the time belongs to the Local type, that is, it should be converted to the Local time zone during deserialization. If this part does not exist, the time is deserialized to Utc.
Modify the Person class and add LastLoginTime:

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Public class Person { Public string Name {get; set ;} Public int Age {get; set ;} Public DateTime LastLoginTime {get; set ;} } Person p = new Person (); P. Name = "James "; P. Age = 28; P. LastLoginTime = DateTime. Now; String jsonString = JsonHelper. JsonSerializer <Person> (p );

Serialization result:
{"Age": 28, "LastLoginTime": "/Date (1294499956278 + 0800)/", "Name": "James "}
1. Use a regular expression to replace the regular expression in the background. Modify JsonHelper:

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Using System; Using System. Collections. Generic; Using System. Linq; Using System. Web; Using System. Runtime. Serialization. Json; Using System. IO; Using System. Text; Using System. Text. RegularExpressions; /// <Summary> /// JSON serialization and deserialization helper class /// </Summary> Public class JsonHelper { /// <Summary> /// JSON serialization /// </Summary> Public static string JsonSerializer <T> (T t) { DataContractJsonSerializer ser = new DataContractJsonSerializer (typeof (T )); MemoryStream MS = new MemoryStream (); Ser. WriteObject (MS, t ); String jsonString = Encoding. UTF8.GetString (ms. ToArray ()); Ms. Close (); // Replace the Json Date string String p = @ "\/Date (d +) + d + )\/"; MatchEvaluator matchEvaluator = new MatchEvaluator (ConvertJsonDateToDateString ); Regex reg = new Regex (p ); JsonString = reg. Replace (jsonString, matchEvaluator ); Return jsonString; } /// <Summary> /// JSON deserialization /// </Summary> Public static T JsonDeserialize <T> (string jsonString) { // Convert the string in the format of "yyyy-MM-dd HH: mm: ss" to "/Date (1294499956278 + 0800 )/". String p = @ "d {4}-d {2}-d {2} sd {2}: d {2}: d {2 }"; MatchEvaluator matchEvaluator = new MatchEvaluator (ConvertDateStringToJsonDate ); Regex reg = new Regex (p ); JsonString = reg. Replace (jsonString, matchEvaluator ); DataContractJsonSerializer ser = new DataContractJsonSerializer (typeof (T )); MemoryStream MS = new MemoryStream (Encoding. UTF8.GetBytes (jsonString )); T obj = (T) ser. ReadObject (MS ); Return obj; } /// <Summary> /// Convert the Json serialization time from/Date (1294499956278 + 0800) to a string /// </Summary> Private static string ConvertJsonDateToDateString (Match m) { String result = string. Empty; DateTime dt = new DateTime (1970, 1, 1 ); Dt = dt. AddMilliseconds (long. Parse (m. Groups [1]. Value )); Dt = dt. ToLocalTime (); Result = dt. ToString ("yyyy-MM-dd HH: mm: ss "); Return result; } /// <Summary> /// Convert the time string to Json time /// </Summary> Private static string ConvertDateStringToJsonDate (Match m) { String result = string. Empty; DateTime dt = DateTime. Parse (m. Groups [0]. Value ); Dt = dt. ToUniversalTime (); TimeSpan ts = dt-DateTime. Parse ("1970-01-01 "); Result = string. Format ("\/Date ({0} + 0800) \/", ts. TotalMilliseconds ); Return result; } }

Serialization Demo:

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Person p = new Person (); P. Name = "James "; P. Age = 28; P. LastLoginTime = DateTime. Now; String jsonString = JsonHelper. JsonSerializer <Person> (p );

Running result:

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{"Age": 28, "LastLoginTime": "01:00:56", "Name": "James "} Deserialization Demo: String json = "{" Age ": 28," LastLoginTime ":" 00:30:00 "," Name ":" James "}"; P = JsonHelper. JsonDeserialize <Person> (json );