using Newtonsoft.Json;
using System.IO;

public class Info
{
    public string FileName { get; set; }
    public int ImgWidth { get; set; }
    public int ImgHeight { get; set; }
    public int LocationX { get; set; }
    public int LocationY { get; set; }
}

private void WriteJson()
{
    //建立資料
    List<Info> listInfoModel = new List<Info>()
    {
        new ImgInfo() { FileName ="test1", ImgWidth = 12, ImgHeight = 13, LocationX = 100, LocationY = 1234},
        new ImgInfo() { FileName ="test2", ImgWidth = 75, ImgHeight = 135, LocationX = 456, LocationY = 9876}
    };
           
    //儲存檔案
    string Filename = "test.json";
    string jsondata = JsonConvert.SerializeObject(listInfoModel);
    File.WriteAllText(Filename, jsondata);
}

private void ReadJson()
    {
        string Filename = "test.json";
        string jsonString = File.ReadAllText(Filename);
        List<Info> test = JsonConvert.DeserializeObject<List<Info>>(jsonString);
        MessageBox.Show(test[0].n_LocationX.ToString());
        MessageBox.Show("OK");
    }

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Newtonsoft.Json;
using System.IO;

namespace v2015Mytest
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        public class ImgInfo
        {
            public string s_FileName { get; set; }
            public int n_ImgWidth { get; set; }
            public int n_ImgHeight { get; set; }
            public int n_LocationX { get; set; }
            public int n_LocationY { get; set; }
        }

        
        //寫Json
        private void button1_Click(object sender, EventArgs e)
        {
            List<ImgInfo> listInfoModel = new List<ImgInfo>()
            {
                new ImgInfo() { s_FileName ="test1", n_ImgWidth = 12, n_ImgHeight = 13, n_LocationX = 100, n_LocationY = 1234},
                new ImgInfo() { s_FileName ="test2", n_ImgWidth = 75, n_ImgHeight = 135, n_LocationX = 456, n_LocationY = 9876}
            };
            
            //MessageBox.Show(JsonConvert.SerializeObject(listInfoModel));

            string Filename = "test.json";
            string jsondata = JsonConvert.SerializeObject(listInfoModel);
            File.WriteAllText(Filename, jsondata);
            MessageBox.Show("OK");
        }
        //讀Json
        private void button2_Click(object sender, EventArgs e)
        {
            string Filename = "test.json";
            string jsonString = File.ReadAllText(Filename);
            List<ImgInfo> test = JsonConvert.DeserializeObject<List<ImgInfo>>(jsonString);
            MessageBox.Show(test[1].n_LocationX.ToString());
            MessageBox.Show("OK");
        }
    }
}