在ASP.Net Core 2.2中，可以通过自定义序列化器来设置输入和输出的序列化器分离。下面是一个包含代码示例的解决方法：

1. 首先，创建一个自定义的JsonInputFormatter类，继承自AspNetCore提供的JsonInputFormatter类：

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Formatters;
using Microsoft.Net.Http.Headers;
using Newtonsoft.Json;
using System;
using System.IO;
using System.Text;
using System.Threading.Tasks;

namespace YourNamespace
{
    public class SeparateSerializerInputFormatter : JsonInputFormatter
    {
        public SeparateSerializerInputFormatter(JsonSerializerSettings serializerSettings, ArrayPool charPool, ObjectPoolProvider objectPoolProvider, MvcOptions options, ILogger logger) : base(serializerSettings, charPool, objectPoolProvider, options, logger)
        {
        }

        public override async Task ReadRequestBodyAsync(InputFormatterContext context, Encoding encoding)
        {
            var request = context.HttpContext.Request;
            var contentType = context.HttpContext.Request.ContentType;
            var mediaType = new MediaType(contentType);

            var serializerSettings = new JsonSerializerSettings
            {
                ContractResolver = new DefaultContractResolver(),
                DateTimeZoneHandling = DateTimeZoneHandling.Utc,
                DateFormatHandling = DateFormatHandling.IsoDateFormat
            };

            if (mediaType.MatchesContentType(MediaTypeHeaderValue.Parse("application/xml")))
            {
                // Use XML deserializer for input
                var xmlSerializer = new XmlSerializer(typeof(YourInputModel));
                var inputModel = (YourInputModel)xmlSerializer.Deserialize(request.Body);
                return await InputFormatterResult.SuccessAsync(inputModel);
            }
            else if (mediaType.MatchesContentType(MediaTypeHeaderValue.Parse("application/json")))
            {
                // Use JSON deserializer for input
                var json = await new StreamReader(request.Body).ReadToEndAsync();
                var inputModel = JsonConvert.DeserializeObject(json, serializerSettings);
                return await InputFormatterResult.SuccessAsync(inputModel);
            }

            return await InputFormatterResult.FailureAsync();
        }
    }
}

2. 然后，在Startup.cs文件中注册这个自定义的JsonInputFormatter类，替换掉默认的JsonInputFormatter：

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using YourNamespace;

namespace YourNamespace
{
    public class Startup
    {
        // ...

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers(options =>
            {
                options.InputFormatters.Insert(0, new SeparateSerializerInputFormatter(new JsonSerializerSettings(), ArrayPool.Shared, ObjectPoolProvider.Create(), options, NullLogger.Instance));
            });
        }

        // ...
    }
}

这样就实现了输入和输出的序列化器设置分离。在自定义的JsonInputFormatter类中，根据请求的Content-Type来判断使用XML序列化器还是JSON序列化器，然后分别进行反序列化操作。你可以根据自己的需求，自定义更多的序列化器。