Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;
using InternetMall.Models;
using InternetMall.DBContext;

namespace InternetMall
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            var builder = new ConfigurationBuilder()
               .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        public void ConfigureServices(IServiceCollection services)
        {

            services.AddDbContext<ModelContext>(options => options.UseOracle(Configuration.GetConnectionString("OracleDBContext")));

            services.AddHttpContextAccessor(); //注册Cookie相关
            services.AddRazorPages();   //注册Razor
            services.AddControllersWithViews();  //注册Controller与Views
        }

        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            { 
                app.UseHsts();
            }

            //设置URL状态
            app.Use(async (context, next) =>
            {
                await next.Invoke();
                if (context.Response.StatusCode == 404)
                {
                    context.Response.Redirect("/Error/Error404");
                }
            });

            app.UseHttpsRedirection();
            app.UseStaticFiles();
            app.UseRouting();
            app.UseAuthorization();
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapRazorPages();
                endpoints.MapControllerRoute(
                    name: "default",
                    pattern: "{controller=Home}/{action=Index}/{id?}");
            });
        }
    }
}