[.Net] .net core中编辑json配置文件的方法

public class TopicConfig
{
    public string Project { get; set; } ="ibms";
    public string Device { get; set; } = "gateway";
    public string City { get; set; } = "wuhan";
    public string Area { get; set; } = "poly";
}

private TopicConfig topicConfig = new TopicConfig();

{
  "topic": {
    "Project": "ibms",
    "Device": "gateway",
    "City": "wuhan",
    "Area": "poly"
  }
}

private void LoadConfig()
    {
      var path = Directory.GetCurrentDirectory();
      var config_file = "appsettings.json";
      var full_path = Path.Combine(path, config_file);
      if (File.Exists(full_path))
      {
        var builder = new ConfigurationBuilder()
          .SetBasePath(path)
          .AddJsonFile("appsettings.json");
        IConfiguration Configuration = builder.Build();
        if (Configuration.GetSection(Topic).Exists())//Topic为字符串常量，对应配置段属性名称
          Configuration.GetSection(Topic).Bind(topicConfig);//绑定配置数据到配置类
      }
      else
      {
        SaveConfig();
      }
   }

private void SaveConfig(string path = "")
{
    if (path == "") path = Directory.GetCurrentDirectory();
    Dictionary<string, object> sectionsInfo = new Dictionary<string, object>();
    sectionsInfo.Add(Topic, topicConfig); //Topic为字符串常量，对应配置段属性名称
    JsonConfigHelper.SaveJson(sectionsInfo, path);
}

using System;
using System.Collections.Generic;
using System.IO;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
namespace flyfire.Common
{
  public class JsonConfigHelper
  {
    public static bool SaveJson(Dictionary<string,object> sectionInfo, string configFilePath, string configFileName = "appsettings.json")
    {
      if (sectionInfo.Count==0)
        return false;
      try
      {
        var filePath = Path.Combine(configFilePath, configFileName);
        JObject jsonObject;
        if (File.Exists(filePath))
        {
          using (StreamReader file = new StreamReader(filePath))
          {
            using (JsonTextReader reader = new JsonTextReader(file))
            {
              jsonObject = (JObject)JToken.ReadFrom(reader);
            }
          }
        }
        else
        {
          jsonObject = new JObject();
        }
        foreach (var key in sectionInfo.Keys)
        {
          jsonObject[key] = JObject.FromObject(sectionInfo[key]);
        }
        using (var writer = new StreamWriter(filePath))
        using (JsonTextWriter jsonwriter = new JsonTextWriter(writer)
        {
          Formatting = Formatting.Indented,//格式化缩进
          Indentation = 4,  //缩进四个字符
          IndentChar = ' '  //缩进的字符是空格
        })
        {
          jsonObject.WriteTo(jsonwriter);
          return true;
        }
      }
      catch (Exception)
      {
        return false;
      }
    }
  }
}