access to xmlhttprequest at blocked by cors policy .net core 6.0

Question

I have 2 projects in ASP.Net Core 6.0. One is CMS(admin side) and other one is user side. I am trying to save a file through CMS project side ajax to user sider project.File saved successfully but i got an error

Access to XMLHttpRequest at 'https://localhost:7212/api/ManageAttachment/UploadminutesAttachment' from origin 'https://localhost:7056' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Please help me out.

Ajax form CMS project

            if (!$('#MinutesAndDecisions').valid()) {
                e.preventDefault();
                return false;
            }

            var files = $('#fileUpload').prop("files");
            var url = '@Constants.FileUploadPath' + 'UploadminutesAttachment'
            formData = new FormData();
            formData.append("MyUploader", files[0]);
            $.ajax({
                type: 'POST',
                url: url,
                data: formData,
                cache: false,
                contentType: false,
                processData: false,
                success: function(repo) {
                    console.log(repo)
                },
                error: function() {
                    alert("Error occurs");
                }
            });
        });

User Side function

        [HttpPost]
        [Route("UploadminutesAttachment")]
        public UploadFileResponse UploadminutesAttachment(IFormFile MyUploader)
        {
            string FolderName = "Documents/minutes";
            var response= UploadAttachment(MyUploader, FolderName).Result;
            return new UploadFileResponse { Path=response.Path, Status=response.Status,Ext=response.Ext};
        }
        [HttpPost]
        [Route("UploadAttachment")]
        private async Task<UploadFileResponse> UploadAttachment(IFormFile MyUploader, string FolderName)
        {
            UploadFileResponse uploadFileResponse = new UploadFileResponse();
            if (MyUploader != null)
            {
                var fileName = Path.GetFileName(MyUploader.FileName);
                string ext = Path.GetExtension(MyUploader.FileName);
                if (ext.ToLower() != ".pdf")
                {
                }
                var filePath = Path.Combine(_hostingEnv.WebRootPath, FolderName, MyUploader.Name + ext);

                using (var fileSteam = new FileStream(filePath, FileMode.Create))
                {
                    await MyUploader.CopyToAsync(fileSteam);
                }

                uploadFileResponse.Status = true;
                uploadFileResponse.Path = "/" + FolderName + "/" + MyUploader.Name + ext;
                uploadFileResponse.Ext = "ext";
            }
            else
            {
                uploadFileResponse.Status = false;
                uploadFileResponse.Path = "";
                uploadFileResponse.Ext = "";
            }
            return uploadFileResponse;
        }

Program.cs from CMS Project and user side project side is same

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
//var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
var connectionString = Constants.DefaultConnectionString; 
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(connectionString));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
    .AddEntityFrameworkStores<ApplicationDbContext>();
builder.Services.AddControllersWithViews();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseMigrationsEndPoint();
}
else
{
    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();

app.UseRouting();

app.UseAuthentication();
app.UseAuthorization();

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

app.Run();

Answer 1

You need to configure Cross-Origin Requests in your user side:

builder.Services.AddCors(options =>
{
    options.AddDefaultPolicy(
        builder =>
        {

          //you can configure your custom policy
            builder.AllowAnyOrigin()
                                .AllowAnyHeader()
                                .AllowAnyMethod();
        });
});

//.............

app.UseCors();

More details you can refer to this Documents;