CSharp中的常用的JSON库-Newtonsoft.Json

前言

在C#中，我们通常使用Newtonsoft.Json库（也称为Json.NET）来处理JSON数据。这个库提供了丰富的功能来序列化和反序列化JSON数据。

官网：

https://www.newtonsoft.com/json

NuGet安装：

Install-Package Newtonsoft.Json -Version 13.0.3

工具类

using System;
using System.Collections.Generic;
using System.IO;
using Newtonsoft.Json;

public class ZJsonHelper
{
  /// <summary>
  /// 类对像转换成json格式
  /// </summary>
  /// <returns>
  /// </returns>
  public static string ToJson(object? t)
  {
    if (t != null)
    {
      return JsonConvert.SerializeObject(
        t,
        Formatting.None,
        new JsonSerializerSettings { NullValueHandling = NullValueHandling.Include }
      );
    }

    return "";
  }

  /// <summary>
  /// 类对像转换成json格式
  /// </summary>
  /// <param name="t">
  /// </param>
  /// <param name="hasNullIgnore">
  /// 是否忽略NULL值
  /// </param>
  /// <returns>
  /// </returns>
  public static string ToJson(object t, bool hasNullIgnore)
  {
    try
    {
      if (hasNullIgnore)
      {
        return JsonConvert.SerializeObject(
          t,
          Formatting.Indented,
          new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore }
        );
      }

      return ToJson(t);
    }
    catch (Exception)
    {
      // ignored
    }

    return "";
  }

  /// <summary>
  ///     JSON字符串转对象
  /// </summary>
  /// <typeparam name="T">
  /// </typeparam>
  /// <param name="strJson">
  /// </param>
  /// <returns>
  /// </returns>
  public static T? JsonToObj<T>(string strJson) where T : class
  {
    //Console.WriteLine("strJson:" + strJson);
    try
    {
      if (!string.IsNullOrEmpty(strJson))
      {
        return JsonConvert.DeserializeObject<T>(strJson);
      }
    }
    catch (Exception)
    {
      // ignored
    }

    return null;
  }

  /// <summary>
  ///     JSON字符串转列表
  /// </summary>
  /// <typeparam name="T"></typeparam>
  /// <param name="respstr"></param>
  /// <returns></returns>
  public static List<T> JsonToList<T>(string respstr)
  {
    try
    {
      JsonSerializer serializer = new JsonSerializer();
      StringReader sr = new StringReader(respstr);
      object? o = serializer.Deserialize(new JsonTextReader(sr), typeof(List<T>));
      if (o is List<T> list)
      {
        return list;
      }
    }
    catch (Exception)
    {
      // ignored
    }

    return new List<T>();
  }

  /// <summary>
  ///     对象转对象
  /// </summary>
  /// <typeparam name="T"></typeparam>
  /// <param name="obj"></param>
  /// <returns></returns>
  public static T? ObjToObj<T>(T? obj) where T : class
  {
    try
    {
      if (obj != null)
      {
        T? jsonToObj = JsonToObj<T>(ToJson(obj));
        return jsonToObj;
      }
    }
    catch (Exception)
    {
      // ignored
    }

    return default;
  }

  /// <summary>
  ///     列表转为新的列表
  /// </summary>
  /// <typeparam name="T"></typeparam>
  /// <param name="list"></param>
  /// <returns></returns>
  public static List<T> ListToList<T>(List<T>? list)
  {
    try
    {
      if (list != null)
      {
        return JsonToList<T>(ToJson(list));
      }
    }
    catch (Exception)
    {
      // ignored
    }

    return new List<T>();
  }
}

忽略NULL值属性

//过滤掉NULL值的属性
JsonSerializerSettings jsonSetting = new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore };
return JsonConvert.SerializeObject(
    obj,
    Formatting.Indented,
    jsonSetting
);