C#純技術之Class寫入Json

   /// <summary>
        /// 寫入json檔案
        /// </summary>
        /// <param name="obj"></param>
        /// <param name="savePath"></param>
        public static void ConvertToJson(object obj, string savePath)
        {
            string str = JsonConvert.SerializeObject(obj);
 
            //json格式化
            JsonSerializer jsonSerializer = new JsonSerializer();
            TextReader textReader = new StringReader(str);
            JsonTextReader jsonTextReader = new JsonTextReader(textReader);
            object _object = jsonSerializer.Deserialize(jsonTextReader);
            if (_object != null)
            {
                StringWriter stringWriter = new StringWriter();
                JsonTextWriter jsonWriter = new JsonTextWriter(stringWriter)
                {
                    Formatting = Formatting.Indented,
                    Indentation = 4,
                    IndentChar = ' '
                };
                jsonSerializer.Serialize(jsonWriter, _object);
                File.WriteAllText(savePath, stringWriter.ToString());
            }
        }

{
  "name": "張三",
  "age": 20,
  "idCard": "123456789",
  "birthday": "2021-01-01 00:00:00",
  "hobbys": [
    {
      "sort": 1,
      "desc": "寫字"
    },
    {
      "sort": 2,
      "desc": "游泳"
    }
  ]
}

private class Studet
{
    public string name { get; set; }
    public int age { get; set; }
    public string idCard { get; set; }
    public DateTime birthday { get; set; }
    public List<hobby> hobbys { get; set; }
}
private class hobby
{
    public int sort { get; set; }
    public string desc { get; set; }
}

//需新增參照：System.Web.Extensions
//需匯入名稱空間：using System.Web.Script.Serialization;
 
 
//json.txt中的資料為上面的json資料
string json = File.ReadAllText("d:\json.txt");
 
 
JavaScriptSerializer jss = new JavaScriptSerializer();
//反序列化成Studet物件
Studet student = jss.Deserialize<Studet>(json);
//然後就可以直接用操作物件的方法直接點出來就行
//輸出:張三
Console.WriteLine(student.name);
 
 
//同樣的，我們可以將上面的物件序列化成一個json資料
//序列化成json
string resultJson = jss.Serialize(student);
Console.WriteLine(resultJson);

//需新增參照：Newtonsoft.Json
//需匯入名稱空間：using Newtonsoft.Json; using Newtonsoft.Json.Linq;
 
 
 //反序列化成物件
Studet student = JsonConvert.DeserializeObject<Studet>(json);
//輸出:張三
Console.WriteLine(student.name);
 
 
//序列化成json
string resultJson = JsonConvert.SerializeObject(student);
Console.WriteLine(resultJson);

//使用JObject（JSON.NET）
//反序列化成JObject
JObject jobj = JObject.Parse(json);
//輸出:張三
Console.WriteLine(jobj["name"].ToString());
//解析hobbys
 JArray jarr = JArray.Parse(jobj["hobbys"].ToString());
//迭代jarr即可
 
 
//同樣的，假如我們有一個JObject物件
 JObject obj = new JObject();
 obj["name"] = "張三";
 obj["age"] = 20;
 //輸出json資料，直接ToString()就可以
 Console.WriteLine(obj.ToString());

//第一種：DataTable
DataTable dt = JsonConvert.DeserializeObject<DataTable>(json);
//或者使用JavaScriptSerializer
dt =jss.Deserialize<DataTable>(json);
//解析DataTable即可
 
 
//第二種：JArray
JArray jarr = JArray.Parse(json);
//然後去迭代jarr即可
foreach (var j in jarr)
{
    Console.WriteLine(j["key"]);
}
 
 
//第三種，也就是我們上面提到了有實體類的情況下
List<Studet> list = JsonConvert.DeserializeObject<List<Studet>>(json);