Question

尝试在我的开发博客上上传帖子时遇到问题。我正在尝试使用MVC框架上传帖子。我正在尝试遵循有关如何构建博客的大量指南。

这是Post课

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Threading.Tasks;

namespace ProjectWebApp.Models
{
    public class Post
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int PostID { get; set; }
        [Required]
        public string Title { get; set; }
        [Required]
        public string Content { get; set; }
        public string Author { get; set; }
        public int Likes { get; set; }
        [Required]
        public DateTime DateCreated { get; set; }
        public DateTime? DateUpdated { get; set; }
        public ICollection<PostTag> PostTags { get; set; }
    }
}

这是BlogDBContext：


using Project.Models;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace ProjectBlogWebApp.Data
{
    public class BlogDbContext : DbContext
    {
        public BlogDbContext(DbContextOptions<BlogDbContext> options) : base(options)
        {
            Database.EnsureDeleted();
            if (Database.EnsureCreated() == true)
            {
                Database.EnsureCreated();
            }
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<PostTag>().HasKey(p => new {p.PostID, p.TagID});
            modelBuilder.Entity<PostTag>().HasOne(pt => pt.Post).WithMany(p => p.PostTags)
                .HasForeignKey(pt => pt.PostID);
            modelBuilder.Entity<PostTag>().HasOne(pt => pt.Tag).WithMany(t => t.PostTags)
                .HasForeignKey(pt => pt.TagID);
        }



        public DbSet<Post> Posts { get; set; }

        public DbSet<Tag> Tags { get; set; }

        public DbSet<PostTag> PostTags { get; set; }
    }
}

这是PostController类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using ProjectWebApp.Data;
using ProjectWebApp.Models;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.EntityFrameworkCore;

namespace ProjectWebApp.Controllers
{
    public class PostController : Controller
    {
        private BlogDbContext _dbBlogContext;

        public PostController(BlogDbContext dbContext)
        {
            _dbBlogContext = dbContext;
        }

        public IActionResult Index()
        {
            var postList = _dbBlogContext.Posts.ToList();

            return View(postList);
        }
        [HttpGet, Route("Create")]
        public IActionResult Create()
        {
            return View(new Post());
        }

        [HttpGet, Route("Edit")]
        public IActionResult Edit()
        {
            
            return View();
        }

        [HttpPost]
        public async Task<IActionResult> CreatePostAsync([Bind("Title", "Content")] Post post)
        {
            try 
            {
                post.Likes = 0;
                post.DateCreated = DateTime.Now;
                post.Author = "Leonard Morrison";
                _dbBlogContext.Add(post);
                await _dbBlogContext.SaveChangesAsync();

                
            }

            catch (DbUpdateException)
            {
                ModelState.TryAddModelError( "Error: Post was not added properly!", "Sorry, the Post was not added properly. Please let me know if this problem persists");
            }

            return View(post);
        }

        [HttpGet]
        public IActionResult Show(int ID)
        {
            var post = getPost(ID);
            return View(post);
        }

        [HttpGet]
        public IActionResult Edit(int ID)
        {
            var post = getPost(ID);
            return View(post);
        }
        [HttpPatch]
        public IActionResult Update(int id)
        {
            var post = _dbBlogContext.Posts.Find(id);
            _dbBlogContext.Posts.Update(post);
            return RedirectToAction("Index");
            
        }

        [HttpDelete]
        public IActionResult RemovePost(int id)
        {
            Post deletedPost = getPost(id);

            _dbBlogContext.Posts.Remove(deletedPost);

            _dbBlogContext.SaveChanges();

            return RedirectToAction("Index");
        }


        public Post getPost(int ID)
        {
            var post = _dbBlogContext.Posts.First(p => p.PostID == ID);

            return post;
        }

    }
}

最后，这是启动源代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using ProjectWebApp.Data;
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 Microsoft.EntityFrameworkCore;
using Microsoft.AspNetCore.Http;


namespace ProjectBlogWebApp
{
    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.AddControllersWithViews();


            services.AddDbContext<BlogDbContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

            services.AddScoped<BlogDbContext, BlogDbContext>();

        }

        // 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.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.UseAuthorization();

            //The Main EndPoint Routes
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllerRoute(
                    name: "default",
                    pattern: "{controller=Home}/{action=Index}/{id}");
            });
            
            //The Post Endpoints Routes
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllerRoute(name: "post",
                    pattern: "{controller=Post}/{action=Index}/{title?}");

            });
        }
    }
}

因为我不知道错误在哪里。但是我需要知道405错误的来源。

谢谢。

Answer 1

检查您的创建视图（Create.cshtml），以确保表单标签中的asp-action =“ CreatePostAsync”。

如果这不是问题，请同时包含您的查看代码。

还要在CreatePostAsync处设置一个断点，然后继续观察错误发生的位置。动作可能没有被触发。也就是说，您的断点也不会被触发。

很少有其他可以帮助解决问题和/或解决问题的方法：

BlogDbContext：OnModelCreating（），这些代码是否表示外键？只要属性名称为{TableName} Id，EF就会自动创建/映射外键。您还可以通过对ForeignKey使用[ForeignKey]属性来明确显示
控制器：您可以将方法和路由[HttpGet（“ Create”）]组合在一起。我敢肯定这不是问题，只是想让您知道
Create（）：无需将新的Post模型传递给view（），因为您的视图已经具有“ @model Post”
CreatePostAsync（）：我建议创建一个具有必要属性和验证检查的PostViewModel。使用PostViewModel作为参数。这也意味着您需要将创建视图从@model Post更新为@model PostViewModel
CreatePostAsync（）：处理完成后，请始终将post方法重定向回去获取。如果有错误，只有您应该返回View（）的时间才会出现。否则，用户可以垃圾邮件刷新并创建多行数据。一旦创建成功，就可以亲自尝试一下

Answer 2

“超文本传输协议（HTTP）405方法不允许”响应状态代码指示服务器知道该请求方法，但目标资源不支持该请求方法。

生成Url为"localhost:5001/Create"，仅与Create Get方法匹配，而表单发送HttpPost请求，因此发生405错误。

1。您可以在表单标签上添加一个asp-action="CreatePost"，

2。或者只是在CreatePost操作上添加相同的Route属性

[HttpPost]
[Route("Create")]
public async Task<IActionResult> CreatePostAsync([Bind("Title", "Content")] Post post)

尝试在我的项目上上传帖子时遇到405错误

2 个答案: