对于使用。net Core 3.1的UTF8编码的JSON文件，我最终能够使用基于微软的信息:https://learn.microsoft.com/en-us/dotnet/standard/serialization/system-text-json-how-to#utf8jsonreader-utf8jsonwriter-and-jsondocument的JsonDocument

string allLinesAsOneString = string.Empty;
string [] lines = File.ReadAllLines(filename, Encoding.UTF8);
foreach(var line in lines)
    allLinesAsOneString += line;

JsonDocument jd = JsonDocument.Parse(Encoding.UTF8.GetBytes(allLinesAsOneString));
var writer = new Utf8JsonWriter(Console.OpenStandardOutput(), new JsonWriterOptions
{
    Indented = true
});
JsonElement root = jd.RootElement;
if( root.ValueKind == JsonValueKind.Object )
{
    writer.WriteStartObject();
}
foreach (var jp in root.EnumerateObject())
    jp.WriteTo(writer);
writer.WriteEndObject();

writer.Flush();

你可以使用以下标准方法来获取格式化的Json

JsonReaderWriterFactory。CreateJsonWriter(流流，编码编码，bool ownsStream, bool缩进，字符串indentChars)

只设置"缩进==true"

试试这样的方法

    public readonly DataContractJsonSerializerSettings Settings = 
            new DataContractJsonSerializerSettings
            { UseSimpleDictionaryFormat = true };

    public void Keep<TValue>(TValue item, string path)
    {
        try
        {
            using (var stream = File.Open(path, FileMode.Create))
            {
                //var currentCulture = Thread.CurrentThread.CurrentCulture;
                //Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;

                try
                {
                    using (var writer = JsonReaderWriterFactory.CreateJsonWriter(
                        stream, Encoding.UTF8, true, true, "  "))
                    {
                        var serializer = new DataContractJsonSerializer(type, Settings);
                        serializer.WriteObject(writer, item);
                        writer.Flush();
                    }
                }
                catch (Exception exception)
                {
                    Debug.WriteLine(exception.ToString());
                }
                finally
                {
                    //Thread.CurrentThread.CurrentCulture = currentCulture;
                }
            }
        }
        catch (Exception exception)
        {
            Debug.WriteLine(exception.ToString());
        }
    }

注意线条

    var currentCulture = Thread.CurrentThread.CurrentCulture;
    Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;
    ....
    Thread.CurrentThread.CurrentCulture = currentCulture;

对于某些类型的xml序列化器，您应该使用InvariantCulture来避免在具有不同区域设置的计算机上反序列化期间出现异常。例如，double或DateTime的无效格式有时会导致错误。

在反序列化

    public TValue Revive<TValue>(string path, params object[] constructorArgs)
    {
        try
        {
            using (var stream = File.OpenRead(path))
            {
                //var currentCulture = Thread.CurrentThread.CurrentCulture;
                //Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;

                try
                {
                    var serializer = new DataContractJsonSerializer(type, Settings);
                    var item = (TValue) serializer.ReadObject(stream);
                    if (Equals(item, null)) throw new Exception();
                    return item;
                }
                catch (Exception exception)
                {
                    Debug.WriteLine(exception.ToString());
                    return (TValue) Activator.CreateInstance(type, constructorArgs);
                }
                finally
                {
                    //Thread.CurrentThread.CurrentCulture = currentCulture;
                }
            }
        }
        catch
        {
            return (TValue) Activator.CreateInstance(typeof (TValue), constructorArgs);
        }
    }

谢谢!

首先我想在Duncan Smart的帖子下添加评论，但不幸的是，我还没有足够的声誉来留下评论。我在这里试试。

我只是想警告一下副作用。

JsonTextReader在内部将json解析为类型化的jtoken，然后将它们序列化回来。

例如，如果您的原始JSON是

{ "double":0.00002, "date":"\/Date(1198908717056)\/"}

美化之后你得到

{ 
    "double":2E-05,
    "date": "2007-12-29T06:11:57.056Z"
}

当然，这两个json字符串是等价的，并且将反序列化为结构上相等的对象，但如果您需要保留原始字符串值，则需要考虑这一点

用JavaScriptSerializer来完成这个任务会很困难。

试试JSON.Net。

对JSON进行了少量修改。净的例子

using System;
using Newtonsoft.Json;

namespace JsonPrettyPrint
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            Product product = new Product
                {
                    Name = "Apple",
                    Expiry = new DateTime(2008, 12, 28),
                    Price = 3.99M,
                    Sizes = new[] { "Small", "Medium", "Large" }
                };

            string json = JsonConvert.SerializeObject(product, Formatting.Indented);
            Console.WriteLine(json);

            Product deserializedProduct = JsonConvert.DeserializeObject<Product>(json);
        }
    }

    internal class Product
    {
        public String[] Sizes { get; set; }
        public decimal Price { get; set; }
        public DateTime Expiry { get; set; }
        public string Name { get; set; }
    }
}

结果

{
  "Sizes": [
    "Small",
    "Medium",
    "Large"
  ],
  "Price": 3.99,
  "Expiry": "\/Date(1230447600000-0700)\/",
  "Name": "Apple"
}

文档:序列化对象

Json的简短示例代码。网络图书馆

private static string FormatJson(string json)
{
    dynamic parsedJson = JsonConvert.DeserializeObject(json);
    return JsonConvert.SerializeObject(parsedJson, Formatting.Indented);
}

onlineer使用Newtonsoft.Json.Linq:

string prettyJson = JToken.Parse(uglyJsonString).ToString(Formatting.Indented);