citys.json 数据源：https://github.com/wecatch/china_regions

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

namespace Jabil.MainControl.Forms
{
    public partial class Form7 : Form
    {
        IFreeSql fsql = FreeFactory.GetSingleton().GetService();
        public Form7()
        {
            InitializeComponent(); 
            this.StartPosition = FormStartPosition.CenterScreen;
        }
        class MyCity
        {
            [Key]
            [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
            public Guid Id { get; set; }
            public string parentCode { get; set; }
            public string provCode { get; set; }
            public string provName { get; set; }
            public string cityCode { get; set; }
            public string cityName { get; set; }
            public string regionCode { get; set; }
            public string regionName { get; set; }
        }
        private void button2_Click(object sender, EventArgs e)
        {
            var tbCount = fsql.Select<MyCity>().Count();
            if (tbCount > 0)
            {
                richTextBox1.Text = "请先删表数据再重新保存结果！" + tbCount;
                return;
            }
            var jsonText = File.ReadAllText(AppDomain.CurrentDomain.BaseDirectory + "/data/area.json");
            //JObject dataView = JsonConvert.DeserializeObject<JObject>(jsonText);
            var dataView = JsonConvert.DeserializeObject<Dictionary<string, object>>(jsonText).ToList();
            //var areas = dataView.Children();

            var provs = dataView.Where(d => d.Key == "86").FirstOrDefault().Value;//所有省份
            var provList = JsonConvert.DeserializeObject<Dictionary<string, object>>(provs.ToString()).ToList();

            var list = new List<MyCity>();
            //先从1级省开始循环
            foreach (var item in provList)
            {
                var provCode = item.Key; var provName = item.Value;
                var mycity = new MyCity()
                {
                    provCode = item.Key,
                    provName = item.Value.ToString(),
                };
                list.Add(mycity);
                var citys = dataView.Where(d => d.Key == item.Key).FirstOrDefault().Value;//所有城市
                var cityList = JsonConvert.DeserializeObject<Dictionary<string, object>>(citys.ToString()).ToList();
                foreach (var item2 in cityList)
                {
                    provCode = item2.Key; provName = item2.Value;
                    mycity = new MyCity()
                    {
                        parentCode = item.Key,
                        provCode = item.Key,
                        provName = item.Value.ToString(),
                        cityCode = item2.Key,
                        cityName = item2.Value.ToString(),
                    };
                    list.Add(mycity);
                    var regions = dataView.Where(d => d.Key == item2.Key).FirstOrDefault().Value;//所有区县
                    if (regions == null || string.IsNullOrEmpty(regions.ToString()))
                    {
                        continue;
                    }
                    var regionList = JsonConvert.DeserializeObject<Dictionary<string, object>>(regions.ToString()).ToList();
                    foreach (var item3 in regionList)
                    {
                        //provCode = item3.Key; provName = item3.Value;
                        mycity = new MyCity()
                        {
                            parentCode = item2.Key,
                            provCode = item.Key,
                            provName = item.Value.ToString(),
                            cityCode = item2.Key,
                            cityName = item2.Value.ToString(),
                            regionCode = item3.Key,
                            regionName = item3.Value.ToString(),
                        };
                        list.Add(mycity);
                    }
                }
            }
            //File.WriteAllText(AppDomain.CurrentDomain.BaseDirectory + "/data.txt", JsonConvert.SerializeObject(list));
            var r = fsql.Insert(list).ExecuteAffrows();
            richTextBox1.Text = r > 0 ? "添加成功" : "添加失败";
        }
    }
}