.net core3.1 CORS跨域处理

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.net core3.1 CORS跨域处理

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.net core3.1是一个LTS版本，这里我们新建一个core3.1的API项目，目录结构如下：

这里序列化使用了Newtonsoft.Json
UserController.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json;
using test.Models;namespace test.Controllers
{[ApiController][Route("[controller]")] public class UserController : Controller{[HttpGet]public ContentResult Index(){List<User> users = new List<User>();users.Add(new User(1, "测试1", 28, "男"));users.Add(new User(2, "测试2", 25, "女"));users.Add(new User(3, "测试3", 22, "女"));List<Order> orders = new List<Order>();orders.Add(new Order(0001,"电脑"));orders.Add(new Order(0002, "手机"));Hashtable result = new Hashtable();result.Add("user", users);result.Add("order", orders);return Content(JsonConvert.SerializeObject(result));}}
}

Order.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;namespace test.Models
{public class Order{public int OrderId { get; set; }public string Product { get; set; }public Order(int OrderId, string Product){this.OrderId = OrderId;this.Product = Product;}}
}

User.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;namespace test.Models
{public class User{public int Id { get; set; }public string Name { get; set; }public int Age { get; set; }public string Gender { get; set; }public User(int Id, string Name, int Age, string Gender){this.Id = Id;this.Name = Name;this.Age = Age;this.Gender = Gender;}}
}

实现跨域需要修改Program.cs和Startup.cs两个文件
Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;namespace test
{public class Program{public static void Main(string[] args){CreateHostBuilder(args).Build().Run();}public static IHostBuilder CreateHostBuilder(string[] args) =>Host.CreateDefaultBuilder(args).ConfigureWebHostDefaults(webBuilder =>{webBuilder.UseStartup<Startup>().//使用*可以在URL用IP访问，默认使用localhostUseUrls("http://*:5000;https://*:5001");});}
}

Startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;namespace test
{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.AddControllers();//跨域设置services.AddCors(options => {options.AddPolicy("any", builder =>{builder.WithOrigins("*");});});}// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.public void Configure(IApplicationBuilder app, IWebHostEnvironment env){if (env.IsDevelopment()){app.UseDeveloperExceptionPage();}app.UseHttpsRedirection();app.UseRouting();//跨域配置，app.UseCors()需要置于app.UseRouting()和app.UseEndpoints之间app.UseCors("any");app.UseAuthorization();app.UseEndpoints(endpoints =>{endpoints.MapControllers();});}}
}

这里我们使用Kestrel启动
用PostMan测试https://主机的IP:5001/User显示实现了跨域处理：