Signalr Hub 中的访问控制允许来源错误

Question

我在 Signalr Hub 中收到“Access-Control-Allow-Origin”错误。项目是“.net 8”

我的program.cs 文件中有这一行。

builder.Services.AddCors(options =>
{
    options.AddPolicy("CORSPolicy",
        builder => builder
        .AllowAnyMethod()
        .AllowAnyHeader()
        .AllowCredentials()
        .SetIsOriginAllowed((hosts) => true));
});
.
.
.
.
.
.
.
.

app.UseCors("CORSPolicy");

Answer 1

使用打击代码可以帮助您解决cors问题。

using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
...

namespace AspCore7_Web_Identity
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);
            ...
            // Add services to the container.
            builder.Services.AddCors(options => options.AddPolicy("CorsPolicy", builder =>
            {
                builder.AllowAnyMethod()
                    .SetIsOriginAllowed(_ => true)
                    .AllowAnyHeader()
                    .AllowCredentials();
            }));

            ...
            builder.Services.AddControllersWithViews();

            builder.Services.AddSignalR();

            var app = builder.Build();

            // Configure the HTTP request pipeline.
            if (!app.Environment.IsDevelopment())
            {
                app.UseExceptionHandler("/Home/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }

            app.UseHttpsRedirection();
            app.UseStaticFiles();
            // Use Cors here
            app.UseCors("CorsPolicy");

            app.UseRouting();

            app.UseAuthorization();

            app.MapControllerRoute(
                name: "default",
                pattern: "{controller=Messaging}/{action=Index}/{id?}");
            app.MapRazorPages();

            app.MapHub<MainHub>("/mainhub");

            app.Run();
        }
    }
}

如果我在信号服务器中禁用 cors 功能，我将面临以下问题。