尽管允许所有来源，但发布到 ASP.NET Core Web 服务器时出现 CORS 错误

Question

每当我从我制作的前端网页向服务器发送发布请求时，开发工具控制台都会抛出以下错误：

Access to fetch at 'http://127.0.0.1:5000/CreateBooking' from origin 'http://127.0.0.1:5500' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

这是我的程序.cs:

using Microsoft.AspNetCore.HttpOverrides;

var builder = WebApplication.CreateBuilder(args);


builder.Services.AddControllers().AddNewtonsoftJson();

builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
builder.Services.AddCors(options =>
{
    options.AddDefaultPolicy(
        builder =>
        {
            builder.WithOrigins("http://127.0.0.1:5500")
            .AllowAnyHeader().AllowAnyMethod();
        }
        );
});
builder.WebHost.UseUrls("http://*:5000");
var app = builder.Build();

app.UseCors();

app.UseStaticFiles();


app.UseForwardedHeaders(new ForwardedHeadersOptions
{
    ForwardedHeaders = ForwardedHeaders.XForwardedFor |
    ForwardedHeaders.XForwardedProto
});

app.UseAuthorization();

app.MapControllers();

app.Run();

要发布即时消息，只需使用带标题的 fetch：“Content-Type”：“application/json”

我尝试过使用通配符来源：

builder.Services.AddCors(options =>
{
    options.AddDefaultPolicy(
        builder =>
        {
            builder.WithOrigins("*")
            .AllowAnyHeader().AllowAnyMethod();
        }
        );
});

但是我仍然遇到同样的错误。我想知道我的构建者是否没有应用该策略，或者我设置策略的方式是否存在本质上的错误。任何帮助将不胜感激，因为这是我的第一个成熟的应用程序并且

Answer 1

来自 CORS 以及命名策略和中间件，

使用端点路由，必须将 CORS 中间件配置为在对 UseRouting 和 UseEndpoints 的调用之间执行。

同样基于

app.UseForwardedHeaders()

，你的中间件管道（结构）应该是：

var app = builder.Build();

app.UseForwardedHeaders(new ForwardedHeadersOptions
{
    ForwardedHeaders = ForwardedHeaders.XForwardedFor |
    ForwardedHeaders.XForwardedProto
});


app.UseStaticFiles();

app.UseRouting();

app.UseCors();

app.UseAuthorization();

app.MapControllers();

app.Run();