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 = 0;
    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":[170,34,54,69,255],"face_name":"zhangsan"}

    //反序列化结构体
    stream1.Position = 0;
    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 = 0;
    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":[170,34,54,69,255],"face_name":"zhangsan01"},
            {"face_Feature":[170,34,54,69,255],"face_name":"zhangsan02"},
            {"face_Feature":[170,34,54,69,255],"face_name":"zhangsan03"},
            {"face_Feature":[170,34,54,69,255],"face_name":"zhangsan04"},
            {"face_Feature":[170,34,54,69,255],"face_name":"zhangsan05"}
        ]

    //反序列化List<T> 
    stream1.Position = 0;
    List<FaceLibrary> p2 = (List<FaceLibrary>)ser.ReadObject(stream1);
    Console.WriteLine(p2[0].face_name);
    Console.WriteLine(p2[0].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
    
*/