【发布时间】：2020-07-09 15:03:29
【问题描述】：
我正在尝试从我的 Angular 应用程序调用我的 .net Core API，但我收到一条错误消息
从源“http://localhost:4200”访问“https://localhost:44378/api/test”处的 XMLHttpRequest 已被 CORS 策略阻止：请求的资源上不存在“Access-Control-Allow-Origin”标头。
我按照 Microsoft 文章的说明对我的 startup.cs 文件进行了所有更改，但仍然出现上述错误。下面是我的 Startup.cs 文件：
public void ConfigureServices(IServiceCollection services)
{
services.AddCors(options =>
{
options.AddPolicy(MyAllowSpecificOrigins,
builder =>
{
builder.WithOrigins("http://localhost:4200")
.AllowAnyHeader()
.AllowAnyOrigin()
.AllowAnyMethod();
});
});
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_3_0);
services.AddControllers();
services.AddDbContext<db_recloadContext>();
}
在我的配置方法中，我有以下代码：
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseHsts();
}
//app.UseCors(MyAllowSpecificOrigins);
app.UseCors(builder => builder
.WithOrigins("http://localhost:4200") /* list of environments that will access this api */
.WithMethods("GET", "OPTIONS") /* assuming your endpoint only supports GET */
.WithHeaders("Origin", "Authorization") /* headers apart of safe-list ones that you use */
);
app.UseHttpsRedirection();
//app.UseMvc();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
我按照以下 Microsoft 文章将 CORS 放入我的 startup.cs 文件中。
https://docs.microsoft.com/en-us/aspnet/core/security/cors?view=aspnetcore-3.1
我尝试了下面给出的代码，我得到了这个错误：
这是修改后的代码：
public void ConfigureServices(IServiceCollection services)
{
services.AddCors(options =>
{
options.AddPolicy("CorsPolicy",
builder =>
{
builder.WithOrigins(new string[] { "http://localhost:4200" }).AllowAnyMethod().AllowAnyHeader();
});
});
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_3_0);
services.AddControllers();
services.AddDbContext<db_recloadContext>();
}
在配置方法中，我有以下代码：
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseHsts();
}
app.UseRouting();
app.UseCors("CorsPolicy");
app.UseHttpsRedirection();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
下面是我的整个 startup.cs 文件：
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;
using Microsoft.AspNetCore.SpaServices;
using RecLoad.Models.DB;
namespace RecLoad
{
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.AddCors(options =>
//{
// options.AddPolicy("AllowAnyCorsPolicy", policy => policy.AllowAnyHeader().AllowAnyMethod().AllowAnyOrigin());
//});
//services.AddCors(options =>
//{
// options.AddPolicy("CorsPolicy",
// builder =>
// {
// builder.WithOrigins("http://localhost:4200")
// .AllowAnyHeader()
// .AllowAnyOrigin()
// .AllowAnyMethod();
// });
//});
services.AddCors(options =>
{
options.AddPolicy("CorsPolicy",
builder =>
{
builder.WithOrigins(new string[] { "http://localhost:4200", "https://localhost:44378/api/recloadprime" }).AllowAnyMethod().WithHeaders("Access-Control-Allow-Origin:http://localhost:4200");
});
});
//response.Headers.Add("Access-Control-Expose-Headers", "Application-Error");
//response.Headers.Add("Access-Control-Allow-Origin", "*");
//services.AddCors(options =>
//{
// options.AddPolicy("AllowAnyCorsPolicy", policy => policy.WithHeaders("Access-Control-Allow-Origin:http://localhost:4200", "Access-Control-Expose-Headers").AllowAnyMethod().AllowAnyOrigin());
//});
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_3_0);
services.AddControllers();
services.AddDbContext<db_recloadContext>();
}
// 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();
}
else
{
app.UseHsts();
}
app.UseCors("CorsPolicy");
app.UseHttpsRedirection();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
}
}
下面是我的控制器：
namespace RecLoad.Controllers
{
[Route("api/[controller]")]
//[EnableCors("AllowAnyCorsPolicy")]
public class RecLoadPrimeController : ControllerBase
{
private readonly db_recloadContext _context;
public RecLoadPrimeController(db_recloadContext context)
{
_context = context;
}
[HttpGet]
public ActionResult<string> Get()
{
return "This is a test";
}
任何帮助将不胜感激。
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