本文主要根据中间件来实现对.net core webapi中产生的请求和响应数据进行获取并存入日志文件中；

这里不详细介绍日志文件的使用。你可以自己接入NLog,log4net，Exceptionless等

创建接口记录的中间件

using Microliu.Core.Loggers;using Microsoft.AspNetCore.Builder;using Microsoft.AspNetCore.Http;using Microsoft.AspNetCore.Http.Internal;using Newtonsoft.Json;using System;using System.Collections.Generic;using System.Diagnostics;using System.IO;using System.Linq;using System.Text;using System.Threading.Tasks;namespace Ptibro.Partner.API.Extensions{  public class RequestResponseLoggingMiddleware  {    private readonly RequestDelegate _next;    private readonly ILogger _logger;    private SortedDictionary<string, object> _data;    private Stopwatch _stopwatch;    public RequestResponseLoggingMiddleware(RequestDelegate next, ILogger logger)    {      _next = next;      _logger = logger;      _stopwatch = new Stopwatch();    }    public async Task Invoke(HttpContext context)    {      _stopwatch.Restart();      _data = new SortedDictionary<string, object>();      HttpRequest request = context.Request;      _data.Add("request.url", request.Path.ToString());      _data.Add("request.headers", request.Headers.ToDictionary(x => x.Key, v => string.Join(";", v.Value.ToList())));      _data.Add("request.method", request.Method);      _data.Add("request.executeStartTime", DateTimeOffset.Now.ToString("yyyy-MM-dd HH:mm:ss.fff"));      // 获取请求body内容      if (request.Method.ToLower().Equals("post"))      {        // 启用倒带功能，就可以让 Request.Body 可以再次读取        request.EnableRewind();        Stream stream = request.Body;        byte[] buffer = new byte[request.ContentLength.Value];        stream.Read(buffer, 0, buffer.Length);        _data.Add("request.body", Encoding.UTF8.GetString(buffer));        request.Body.Position = 0;      }      else if (request.Method.ToLower().Equals("get"))      {        _data.Add("request.body", request.QueryString.Value);      }      // 获取Response.Body内容      var originalBodyStream = context.Response.Body;      using (var responseBody = new MemoryStream())      {        context.Response.Body = responseBody;        await _next(context);        _data.Add("response.body", await GetResponse(context.Response));        _data.Add("response.executeEndTime", DateTimeOffset.Now.ToString("yyyy-MM-dd HH:mm:ss.fff"));        await responseBody.CopyToAsync(originalBodyStream);      }      // 响应完成记录时间和存入日志      context.Response.OnCompleted(() =>      {        _stopwatch.Stop();        _data.Add("elaspedTime", _stopwatch.ElapsedMilliseconds + "ms");        var json = JsonConvert.SerializeObject(_data);        _logger.Debug(json, "api", request.Method.ToUpper());        return Task.CompletedTask;      });    }    /// <summary>    /// 获取响应内容    /// </summary>    /// <param name="response"></param>    /// <returns></returns>    public async Task<string> GetResponse(HttpResponse response)    {      response.Body.Seek(0, SeekOrigin.Begin);      var text = await new StreamReader(response.Body).ReadToEndAsync();      response.Body.Seek(0, SeekOrigin.Begin);      return text;    }  }  /// <summary>  /// 扩展中间件  /// </summary>  public static class RequestResponseLoggingMiddlewareExtensions  {    public static IApplicationBuilder UseRequestResponseLogging(this IApplicationBuilder app)    {      return app.UseMiddleware<RequestResponseLoggingMiddleware>();    }  }}