本文只对api接口，header请求参数进行简单验证，起到抛砖引玉使用，需要深入验证，请自行扩展

　　项目目录结构如图

• 　　中间件类

using ApiMiddleware.Common.DataEnityModel;using ApiMiddleware.Common.DbContext;using Microsoft.AspNetCore.Http;using Microsoft.Extensions.Logging;using Microsoft.Extensions.Primitives;using Newtonsoft.Json;using System;using System.Diagnostics;using System.IO;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ApiMiddleware.Middleware{    public class RequestHeaderVerificationMiddleware    {        private readonly RequestDelegate _next;        private readonly ILogger _logger;        ///         /// 计时器        ///         private Stopwatch _stopwatch;        private const string RESPONSE_HEADER_RESPONSE_TIME = "X-Response-Time-ms";        public RequestHeaderVerificationMiddleware(RequestDelegate next, ILogger logger)        {            _next = next;            _logger = logger;        }        public async Task Invoke(HttpContext context, MySqlMasterDbContext masterDbContext)        {            _stopwatch = new Stopwatch();            _stopwatch.Start();            _logger.LogError($"Handling request: {context.Request.Path}");            if (!context.Request.Headers.TryGetValue("request_id", out StringValues request_id) || string.IsNullOrEmpty(request_id))            {                await HandleMessage(context, JsonConvert.SerializeObject(new { msg = "request_id不可为空", request_id = request_id }));                goto step;            }            if (!context.Request.Headers.TryGetValue("uname", out StringValues uname) || string.IsNullOrEmpty(uname))            {                await HandleMessage(context, JsonConvert.SerializeObject(new { msg = "名称不可为空", request_id = request_id, uname = uname }));                goto step;            }            var stu = new student            {                id = request_id,                stu_name = uname,                createtime = DateTime.Now,                updatetime = DateTime.Now            };            var model = masterDbContext.student.FirstOrDefault(m => m.id == request_id);            if (model == null)                masterDbContext.Add(stu);            else            {                model.stu_name = uname;                model.updatetime = DateTime.Now;                masterDbContext.Update(model);            }            masterDbContext.SaveChanges();            context.Response.OnStarting(() =>            {                // Stop the timer information and calculate the time                  _stopwatch.Stop();                var responseTimeForCompleteRequest = _stopwatch.ElapsedMilliseconds;                // Add the Response time information in the Response headers.                  context.Response.Headers[RESPONSE_HEADER_RESPONSE_TIME] = responseTimeForCompleteRequest.ToString();                return Task.CompletedTask;            });        step:            if (!context.Response.HasStarted)            {                await _next(context);            }        }        ///         /// 错误信息或验证信息处理方法        ///         ///         ///         ///         private async Task HandleMessage(HttpContext context, string msg)        {            context.Response.ContentType = "text/json;charset=utf-8;";            //浏览器在开发环境显示详细错误信息,其他环境隐藏错误信息            await context.Response.WriteAsync(msg);        }    }}

using Microsoft.AspNetCore.Builder;namespace ApiMiddleware.Middleware{    public static class MyMiddlewareExtensions    {        public static void UseMyMiddleware(this IApplicationBuilder builder)        {            builder.UseMiddleware();        }    }}

• 数据库操作类MySqlMasterDbContext

using ApiMiddleware.Common.DataEnityModel;using Microsoft.EntityFrameworkCore;using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;namespace ApiMiddleware.Common.DbContext{    public class MySqlMasterDbContext : Microsoft.EntityFrameworkCore.DbContext    {        private string _conn;        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)        {            if (!string.IsNullOrEmpty(_conn))            {                optionsBuilder.UseMySQL(_conn);            }            base.OnConfiguring(optionsBuilder);        }        public MySqlMasterDbContext(DbContextOptions options) : base(options)        {            Database.EnsureCreated();        }        public MySqlMasterDbContext(string conn)        {            _conn = conn;        }        protected override void OnModelCreating(ModelBuilder builder)        {            base.OnModelCreating(builder);        }        public DbSet student { get; set; }    }}

• 在Startup中注册中间件

using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;using ApiMiddleware.Common.DbContext;using ApiMiddleware.Middleware;using Microsoft.AspNetCore.Builder;using Microsoft.AspNetCore.Hosting;using Microsoft.AspNetCore.HttpsPolicy;using Microsoft.AspNetCore.Mvc;using Microsoft.EntityFrameworkCore;using Microsoft.Extensions.Configuration;using Microsoft.Extensions.DependencyInjection;using Microsoft.Extensions.Logging;using Microsoft.Extensions.Options;namespace ApiMiddleware{    public class Startup    {        public Startup(IConfiguration configuration)        {            Configuration = configuration;        }        public IConfiguration Configuration { get; }        // This method gets called by the runtime. Use this method to add services to the container.        public void ConfigureServices(IServiceCollection services)        {            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);            var identityConn = "Server=localhost;Database=business;Uid=root;Pwd=root;";            services.AddDbContext(options => options.UseMySQL(identityConn));        }        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.        public void Configure(IApplicationBuilder app, IHostingEnvironment env)        {            if (env.IsDevelopment())            {                app.UseDeveloperExceptionPage();            }            else            {                app.UseHsts();            }            app.UseMyMiddleware();//注册中间件            app.UseHttpsRedirection();            app.UseMvc();        }    }}

using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;using ApiMiddleware.Common.DataEnityModel;using Microsoft.AspNetCore.Http;using Microsoft.AspNetCore.Mvc;using Newtonsoft.Json;namespace ApiMiddleware.Controllers{    [Route("api/[controller]")]    [ApiController]    public class StuController : ControllerBase    {        [HttpPost("stuinfo")]        public   ActionResult AddStu([FromBody]StudentExternal info)        {            return  JsonConvert.SerializeObject(new { result="Success",Data=info.data});        }    }}

• 请求实例测试，注意请求头不要带汉字，否则报错

• 如请求头带汉字，则报如下提示