在 NET使用JSON作為資料交換格式
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我們知道在.NET中我們有多種物件序列化的方式,如XML方式序列化、Binary序列化,其中XML序列化是一種比較通用的在各語言之間傳遞資料的方式。除了這兩種序列化方式之外,在.NET中還可以使用JSON序列化。
JSON(JavaScript Object Notation)是一種輕量級輕量級的資料交換格式,並且它獨立於程式語言,與XML序列化相比,JSON序列化後產生的資料一般要比XML序列化後資料體積小,所以在Facebook等知名網站中都採用了JSON作為資料交換方式。在.NET中有三種常用的JSON序列化的類,分別是System.Web.Script.Serialization.JavaScriptSerializer類、System.Runtime.Serialization.Json.DataContractJsonSerializer類和Newtonsoft.Json.JsonConvert類。
為了便於下面的演示,下面提供一個類的程式碼:
- [DataContract]
- public class User
- {
- /// <summary>
- /// 編號
- /// </summary>
- [DataMember]
- public int UserId { get; set; }
- /// <summary>
- /// 使用者名稱
- /// </summary>
- [DataMember]
- public string UserName { get; set; }
- /// <summary>
- /// 建立時間
- /// </summary>
- [DataMember]
- [JsonConverter(typeof(IsoDateTimeConverter))]
- public DateTime CreateDate { get; set; }
- /// <summary>
- /// 生日
- /// </summary>
- [DataMember]
- [JsonConverter(typeof(JavaScriptDateTimeConverter))]
- public DateTime Birthday { get; set; }
- /// <summary>
- /// 相關URL
- /// </summary>
- [DataMember]
- public List<string> Urls { get; set; }
- /// <summary>
- /// 薪水
- /// </summary>
- //[ScriptIgnore]//使用JavaScriptSerializer序列化時不序列化此欄位
- //[IgnoreDataMember]//使用DataContractJsonSerializer序列化時不序列化此欄位
- //[JsonIgnore]//使用JsonConvert序列化時不序列化此欄位
- public int Salary { get; set; }
- /// <summary>
- /// 權利級別
- /// </summary>
- [DataMember]
- public Priority Priority { get; set; }
- public User()
- {
- Urls = new List<string>();
- }
- }
- /// <summary>
- /// 權利級別
- /// </summary>
- public enum Priority:byte
- {
- Lowest=0x1,
- BelowNormal=0x2,
- Normal=0x4,
- AboveNormal=0x8,
- Highest=0x16
- }
使用System.Web.Script.Serialization.JavaScriptSerializer類
System.Web.Script.Serialization.JavaScriptSerializer類是.NET類庫中自帶的一種JSON序列化實現,在.NET Framework3.5及以後版本中可以使用這個類,這個類位於System.Web.Extensions.dll中,使用這個類是必須新增對這個dll的引用。
下面的程式碼是使用JavaScriptSerializer進行序列化和反序列化的例子:
- public static void JavaScriptSerializerDemo()
- {
- User user = new User { UserId = 1, UserName = "李剛", CreateDate = DateTime.Now.AddYears(-30),Birthday=DateTime.Now.AddYears(-50), Priority = Priority.Highest, Salary = 500000 };
- //JavaScriptSerializer類在System.Web.Extensions.dll中,注意新增這個引用
- JavaScriptSerializer serializer = new JavaScriptSerializer();
- //JSON序列化
- string result=serializer.Serialize(user);
- Console.WriteLine("使用JavaScriptSerializer序列化後的結果:{0},長度:{1}", result, result.Length);
- //JSON反序列化
- user = serializer.Deserialize<User>(result);
- Console.WriteLine("使用JavaScriptSerializer反序列化後的結果:UserId:{0},UserName:{1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
- }
說明:如果不想序列化某個欄位,可以在欄位前面加[JsonIgnore]標記。
使用System.Runtime.Serialization.Json.DataContractJsonSerializer類
System.Runtime.Serialization.Json.DataContractJsonSerializer類位於System.ServiceModel.Web.dll中,使用這個類時除了需要新增對System.ServiceModel.Web.dll的引用之外,還需要新增System.Runtime.Serialization.dll的引用,注意這個類也是在.NET Framework3.5及以後版本中可以使用。
下面是使用DataContractJsonSerializer類的例子:
- public static void DataContractJsonSerializerDemo()
- {
- User user = new User { UserId = 1, UserName = "李剛", CreateDate = DateTime.Now.AddYears(-30), Birthday = DateTime.Now.AddYears(-50), Priority = Priority.AboveNormal, Salary = 50000 };
- string result = string.Empty;
- //DataContractJsonSerializer類在System.ServiceModel.Web.dll中,注意新增這個引用
- DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(User));
- using (MemoryStream stream = new MemoryStream())
- {
- //JSON序列化
- serializer.WriteObject(stream, user);
- result = Encoding.UTF8.GetString(stream.ToArray());
- Console.WriteLine("使用DataContractJsonSerializer序列化後的結果:{0},長度:{1}", result, result.Length);
- }
- //JSON反序列化
- byte[] buffer = Encoding.UTF8.GetBytes(result);
- using (MemoryStream stream = new MemoryStream(buffer))
- {
- user = serializer.ReadObject(stream) as User;
- Console.WriteLine("使用DataContractJsonSerializer反序列化後的結果:UserId:{0},UserName:{1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
- }
- }
注意:要使用DataContractJsonSerializer類進行序列化和反序列化,必須給類加上[DataContract]屬性,對要序列化的欄位加上[DataMember]屬性,如果不想序列化某個欄位或者屬性,可以加上[IgnoreDataMember]屬性。
使用Newtonsoft.Json.JsonConvert類
Newtonsoft.Json.JsonConvert類是非微軟提供的一個JSON序列化和反序列的開源免費的類庫(下載網址是:http://www.codeplex.com/json/),它提供了更靈活的序列化和反序列化控制,並且如果你的開發環境使用的是.NET Framework3.5及以後版本的話,你就可以使用Linq to JSON,這樣一來面對一大段的資料不必一一解析,你可以使用Linq to JSON解析出你關心的那部分即可,非常方便。
下面是使用Newtonsoft.Json.JsonConvert類的例子:
- public static void JsonConvertDemo()
- {
- User user = new User { UserId = 1, UserName = "李剛", CreateDate = DateTime.Now.AddYears(-30), Birthday = DateTime.Now.AddYears(-50), Priority = Priority.BelowNormal, Salary = 5000 };
- //JsonConvert類在Newtonsoft.Json.Net35.dll中,注意到http://www.codeplex.com/json/下載這個dll並新增這個引用
- //JSON序列化
- string result = JsonConvert.SerializeObject(user);
- Console.WriteLine("使用JsonConvert序列化後的結果:{0},長度:{1}", result, result.Length);
- //JSON反序列化
- user = JsonConvert.DeserializeObject<User>(result);
- Console.WriteLine("使用JsonConvert反序列化後的結果:UserId:{0},UserName:{1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
- }
- public static void JsonConvertLinqDemo()
- {
- User user = new User { UserId = 1, UserName = "周公", CreateDate = DateTime.Now.AddYears(-8), Birthday = DateTime.Now.AddYears(-32), Priority = Priority.Lowest, Salary = 500, Urls = new List<string> { "http://zhoufoxcn.blog.51cto.com", "http://blog.csdn.net/zhoufoxcn" } };
- //JsonConvert類在Newtonsoft.Json.Net35.dll中,注意到http://www.codeplex.com/json/下載這個dll並新增這個引用
- //JSON序列化
- string result = JsonConvert.SerializeObject(user);
- Console.WriteLine("使用JsonConvert序列化後的結果:{0},長度:{1}", result, result.Length);
- //使用Linq to JSON
- JObject jobject = JObject.Parse(result);
- JToken token = jobject["Urls"];
- List<string> urlList = new List<string>();
- foreach (JToken t in token)
- {
- urlList.Add(t.ToString());
- }
- Console.Write("使用Linq to JSON反序列化後的結果:[");
- for (int i = 0; i < urlList.Count - 1;i++ )
- {
- Console.Write(urlList[i] + ",");
- }
- Console.WriteLine(urlList[urlList.Count - 1] + "]");
- }
注意:如果有不需要序列化的欄位,可以給該欄位新增[JsonIgnore]標記。在Newtonsoft這個類庫中對於日期的序列化有多種方式,可以類的DataTime成員新增上對應的標記,這樣在進行序列化和反序列化時就會按照指定的方式進行,在本例中User類的CreateDate屬性新增的屬性是[JsonConverter(typeof(IsoDateTimeConverter))],而Birthday屬性新增的屬性是[JsonConverter(typeof(JavaScriptDateTimeConverter))],從序列化的結果可以看出來它們最終的表現形式並不一樣。
本文中所有的示例程式碼如下:
[c-sharp] view plain copy print ?
- using System;
- using System.Collections.Generic;
- using System.Linq;
- using System.Text;
- using System.Web.Script.Serialization;
- using System.Runtime.Serialization.Json;
- using System.IO;
- using System.Runtime.Serialization;
- using Newtonsoft.Json;
- using Newtonsoft.Json.Linq;
- using Newtonsoft.Json.Converters;
- namespace JSONDemo
- {
- class Program
- {
- static void Main(string[] args)
- {
- JavaScriptSerializerDemo();
- DataContractJsonSerializerDemo();
- JsonConvertDemo();
- JsonConvertLinqDemo();
- Console.ReadLine();
- }
- public static void JavaScriptSerializerDemo()
- {
- User user = new User { UserId = 1, UserName = "李剛", CreateDate = DateTime.Now.AddYears(-30),Birthday=DateTime.Now.AddYears(-50), Priority = Priority.Highest, Salary = 500000 };
- //JavaScriptSerializer類在System.Web.Extensions.dll中,注意新增這個引用
- JavaScriptSerializer serializer = new JavaScriptSerializer();
- //JSON序列化
- string result=serializer.Serialize(user);
- Console.WriteLine("使用JavaScriptSerializer序列化後的結果:{0},長度:{1}", result, result.Length);
- //JSON反序列化
- user = serializer.Deserialize<User>(result);
- Console.WriteLine("使用JavaScriptSerializer反序列化後的結果:UserId:{0},UserName:{1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
- }
- public static void DataContractJsonSerializerDemo()
- {
- User user = new User { UserId = 1, UserName = "李剛", CreateDate = DateTime.Now.AddYears(-30), Birthday = DateTime.Now.AddYears(-50), Priority = Priority.AboveNormal, Salary = 50000 };
- string result = string.Empty;
- //DataContractJsonSerializer類在System.ServiceModel.Web.dll中,注意新增這個引用
- DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(User));
- using (MemoryStream stream = new MemoryStream())
- {
- //JSON序列化
- serializer.WriteObject(stream, user);
- result = Encoding.UTF8.GetString(stream.ToArray());
- Console.WriteLine("使用DataContractJsonSerializer序列化後的結果:{0},長度:{1}", result, result.Length);
- }
- //JSON反序列化
- byte[] buffer = Encoding.UTF8.GetBytes(result);
- using (MemoryStream stream = new MemoryStream(buffer))
- {
- user = serializer.ReadObject(stream) as User;
- Console.WriteLine("使用DataContractJsonSerializer反序列化後的結果:UserId:{0},UserName:{1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
- }
- }
- public static void JsonConvertDemo()
- {
- User user = new User { UserId = 1, UserName = "李剛", CreateDate = DateTime.Now.AddYears(-30), Birthday = DateTime.Now.AddYears(-50), Priority = Priority.BelowNormal, Salary = 5000 };
- //JsonConvert類在Newtonsoft.Json.Net35.dll中,注意到http://www.codeplex.com/json/下載這個dll並新增這個引用
- //JSON序列化
- string result = JsonConvert.SerializeObject(user);
- Console.WriteLine("使用JsonConvert序列化後的結果:{0},長度:{1}", result, result.Length);
- //JSON反序列化
- user = JsonConvert.DeserializeObject<User>(result);
- Console.WriteLine("使用JsonConvert反序列化後的結果:UserId:{0},UserName:{1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
- }
- public static void JsonConvertLinqDemo()
- {
- User user = new User { UserId = 1, UserName = "周公", CreateDate = DateTime.Now.AddYears(-8), Birthday = DateTime.Now.AddYears(-32), Priority = Priority.Lowest, Salary = 500, Urls = new List<string> { "http://zhoufoxcn.blog.51cto.com", "http://blog.csdn.net/zhoufoxcn" } };
- //JsonConvert類在Newtonsoft.Json.Net35.dll中,注意到http://www.codeplex.com/json/下載這個dll並新增這個引用
- //JSON序列化
- string result = JsonConvert.SerializeObject(user);
- Console.WriteLine("使用JsonConvert序列化後的結果:{0},長度:{1}", result, result.Length);
- //使用Linq to JSON
- JObject jobject = JObject.Parse(result);
- JToken token = jobject["Urls"];
- List<string> urlList = new List<string>();
- foreach (JToken t in token)
- {
- urlList.Add(t.ToString());
- }
- Console.Write("使用Linq to JSON反序列化後的結果:[");
- for (int i = 0; i < urlList.Count - 1;i++ )
- {
- Console.Write(urlList[i] + ",");
- }
- Console.WriteLine(urlList[urlList.Count - 1] + "]");
- }
- }
- [DataContract]
- public class User
- {
- /// <summary>
- /// 編號
- /// </summary>
- [DataMember]
- public int UserId { get; set; }
- /// <summary>
- /// 使用者名稱
- /// </summary>
- [DataMember]
- public string UserName { get; set; }
- /// <summary>
- /// 建立時間
- /// </summary>
- [DataMember]
- [JsonConverter(typeof(IsoDateTimeConverter))]
- public DateTime CreateDate { get; set; }
- /// <summary>
- /// 生日
- /// </summary>
- [DataMember]
- [JsonConverter(typeof(JavaScriptDateTimeConverter))]
- public DateTime Birthday { get; set; }
- /// <summary>
- /// 相關URL
- /// </summary>
- [DataMember]
- public List<string> Urls { get; set; }
- /// <summary>
- /// 薪水
- /// </summary>
- [ScriptIgnore]//使用JavaScriptSerializer序列化時不序列化此欄位
- [IgnoreDataMember]//使用DataContractJsonSerializer序列化時不序列化此欄位
- [JsonIgnore]//使用JsonConvert序列化時不序列化此欄位
- public int Salary { get; set; }
- /// <summary>
- /// 權利級別
- /// </summary>
- [DataMember]
- public Priority Priority { get; set; }
- public User()
- {
- Urls = new List<string>();
- }
- }
- /// <summary>
- /// 權利級別
- /// </summary>
- public enum Priority:byte
- {
- Lowest=0x1,
- BelowNormal=0x2,
- Normal=0x4,
- AboveNormal=0x8,
- Highest=0x16
- }
- }