C# 结构体和List<T>类型数据转Json数据保存和读取

C#  结构体和List<T>类型数据转Json数据保存和读取

 一.结构体转Json

     public struct FaceLibrary
     {
         public string face_name;
         public byte[] face_Feature;
     }

     //序列化结构体
     facelibrary = new FaceLibrary();
     facelibrary.face_name = "zhangsan";
     facelibrary.face_Feature = new byte[] { 0xaa, 0x22, 0x36, 0x45, 0xff };

     MemoryStream stream1 = new MemoryStream();
     DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(FaceLibrary));
     ser.WriteObject(stream1, facelibrary);
     stream1.Position = ;
     StreamReader sr = new StreamReader(stream1);
     Console.Write("JSON form of Person object: ");
     Console.WriteLine(sr.ReadToEnd());

     //打印结果：
         JSON form of Person object: [{"face_Feature":[,,,,],"face_name":"zhangsan"}

     //反序列化结构体
     stream1.Position = ;
     FaceLibrary p2 = (FaceLibrary)ser.ReadObject(stream1);
     Console.WriteLine(p2.face_name);
     Console.WriteLine(p2.face_Feature);
     //输出结果：
         wangjin01
         System.Byte[]

     说明： 通过如上操作，能够将结构体的数据转为Json数据    

 方法二： 将List<T> 结构的数据转为Json数据

     public struct FaceLibrary
     {
         public string face_name;
         public byte[] face_Feature;
     }

     List<FaceLibrary> listfacex = new List<FaceLibrary>();

     //序列化List<T>
     facelibrary = new FaceLibrary();
     facelibrary.face_name = "zhangsan01";
     facelibrary.face_Feature = new byte[] { 0xaa, 0x22, 0x36, 0x45, 0xff };
     listfacex.Add(facelibrary);

     facelibrary.face_name = "zhangsan02";
     facelibrary.face_Feature = new byte[] { 0xaa, 0x22, 0x36, 0x45, 0xff };
     listfacex.Add(facelibrary);

     facelibrary.face_name = "zhangsan03";
     facelibrary.face_Feature = new byte[] { 0xaa, 0x22, 0x36, 0x45, 0xff };
     listfacex.Add(facelibrary);

     facelibrary.face_name = "zhangsan04";
     facelibrary.face_Feature = new byte[] { 0xaa, 0x22, 0x36, 0x45, 0xff };
     listfacex.Add(facelibrary);

     facelibrary.face_name = "zhangsan05";
     facelibrary.face_Feature = new byte[] { 0xaa, 0x22, 0x36, 0x45, 0xff };
     listfacex.Add(facelibrary);

     MemoryStream stream1 = new MemoryStream();
     DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(List<FaceLibrary>));
     ser.WriteObject(stream1, listfacex);
     stream1.Position = ;
     StreamReader sr = new StreamReader(stream1);
     Console.Write("JSON form of Person object: ");
     Console.WriteLine(sr.ReadToEnd());

     //输出结果：
         JSON form of Person object: [
             {"face_Feature":[,,,,],"face_name":"zhangsan01"},
             {"face_Feature":[,,,,],"face_name":"zhangsan02"},
             {"face_Feature":[,,,,],"face_name":"zhangsan03"},
             {"face_Feature":[,,,,],"face_name":"zhangsan04"},
             {"face_Feature":[,,,,],"face_name":"zhangsan05"}
         ]

     //反序列化List<T>
     stream1.Position = ;
     List<FaceLibrary> p2 = (List<FaceLibrary>)ser.ReadObject(stream1);
     Console.WriteLine(p2[].face_name);
     Console.WriteLine(p2[].face_Feature);
     //输出结果：
         zhangsan01
         System.Byte[]

 三.测试应用
     /*
     应用需求：
         1. 通过List<T>将结构体类型<T>的多个数据加载到List<T>中;
         2. 将List<T>数据转为Json数据,并写入到文件中;
         3. 从文件中读取保存的Json数据，并还原成List<T>数据供后续调用;    

         //说明：  JavaScriptSerializer 需要导入相应的库，
             命名空间:   System.Web.Script.Serialization
             程序集:  System.Web.Extensions（位于 System.Web.Extensions.dll）
             参考文件：https://msdn.microsoft.com/zh-cn/library/system.web.script.serialization.javascriptserializer.aspx
     */    

     //1.定义结构体和List<T>
         public struct FaceLibrary
         {
             public string face_name;
             public byte[] face_Feature;
         }
         FaceLibrary facelibrary;
         List<FaceLibrary> listfacex = new List<FaceLibrary>();

     //2. 添加数据到List<T>中
         facelibrary.face_name = "zhangsan01";
         facelibrary.face_Feature = new byte[] { 0xaa, 0x01, 0x11, 0x21, 0xff };
         listfacex.Add(facelibrary);

         facelibrary.face_name = "zhangsan02";
         facelibrary.face_Feature = new byte[] { 0xaa, 0x02, 0x12, 0x22, 0xff };
         listfacex.Add(facelibrary);

         facelibrary.face_name = "zhangsan03";
         facelibrary.face_Feature = new byte[] { 0xaa, 0x03, 0x13, 0x23, 0xff };
         listfacex.Add(facelibrary);

         facelibrary.face_name = "zhangsan04";
         facelibrary.face_Feature = new byte[] { 0xaa, 0x04, 0x14, 0x24, 0xff };
         listfacex.Add(facelibrary);

         facelibrary.face_name = "zhangsan05";
         facelibrary.face_Feature = new byte[] { 0xaa, 0x05, 0x15, 0x25, 0xff };
         listfacex.Add(facelibrary);

     //3. 将List<T>数据转为Json数据
         String str = JsonListToString(listfacex);
         //JSON序列化,将List<T>转换为String
         private String JsonListToString (List<FaceLibrary> list)
         {
             JavaScriptSerializer Serializerx = new JavaScriptSerializer();
             string changestr = Serializerx.Serialize(list);
             return changestr;
         }

     //4. 将Json数据写入文件系统
         FileWrite("test.txt",str)
         //写入文件
         private void FileWrite(string filepath,string writestr)
         {
             FileStream fs = new FileStream(filepath, FileMode.OpenOrCreate);
             StreamWriter sw = new StreamWriter(fs);
             sw.Write(writestr);
             sw.Close();
             fs.Close();
         }

     //5.  从文件中读取Json数据

         string str =  FileRead("test.txt");
         //读取文件
         private string  FileRead(string filepath)
         {
             FileStream fs = new FileStream(filepath, FileMode.Open);
             StreamReader sr = new StreamReader(fs);
             string str = sr.ReadToEnd();
             sr.Close();
             fs.Close();
             return str;
         }

     //6. 将Json数据转换为List<T>数据

         List<FaceLibrary> listface =   StringToJsonList(str)；
         //JSON反序列化,将List<T>转换为String
         private List<FaceLibrary> StringToJsonList(string str)
         {
             JavaScriptSerializer Serializer = new JavaScriptSerializer();
             List<FaceLibrary> face = Serializer.Deserialize<List<FaceLibrary>>(str);
             return face;
         }

 //以上方法基本能够解决上述问题；

 以上代码基于参考如下代码，
 /*
 //    C#将Json字符串反序列化成List对象类集合

     using System.IO;
     using System.Web.Script.Serialization;
     using System.Runtime.Serialization.Json;
     public static List<T> JSONStringToList<T>(this string JsonStr)
     {

         JavaScriptSerializer Serializer = new JavaScriptSerializer();

         List<T> objs = Serializer.Deserialize<List<T>>(JsonStr);

         return objs;

     }

     public static T Deserialize<T>(string json)
     {

         T obj = Activator.CreateInstance<T>();
         using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(json)))
         {

             DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());

             return (T)serializer.ReadObject(ms);
         }

     }

     //好了，我们来测试下
     string JsonStr = "[{Name:'苹果',Price:5.5},{Name:'橘子',Price:2.5},{Name:'柿子',Price:16}]";
     List<Product> products = new List<Product>();
     products = JSONStringToList<Product>(JsonStr);
     //Response.Write(products.Count());
     foreach (var item in products)
     {
         Response.Write(item.Name + ":" + item.Price + "<br />");
     }
     public class Product
     {
         public string Name { get; set; }
         public double Price { get; set; }
     }
     结果：
     苹果:5.5
     橘子:2.5
     柿子:16

 */