如何修复“必需的”注解在.NET中不起作用

Question

我将遵循本教程：https://docs.microsoft.com/en-us/aspnet/core/tutorials/razor-pages/validation?view=aspnetcore-2.2

这是我的电影模型类：

using System;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

public class Movie
{
    public int ID { get; set; }

    [StringLength(60, MinimumLength = 3)]
    [Required]
    public string Title { get; set; }

    [Display(Name = "Release Date")]
    [DataType(DataType.Date)]
    public DateTime ReleaseDate { get; set; }

    [Range(1, 100)]
    [DataType(DataType.Currency)]
    [Column(TypeName = "decimal(18, 2)")]
    public decimal Price { get; set; }

    [RegularExpression(@"^[A-Z]+[a-zA-Z""'\s-]*$")]
    [Required]
    [StringLength(30)]
    public string Genre { get; set; }
}

但是当我在本地测试时，这两个字段：Title和Genre似乎没有我期望的验证，请看下面的截图：

​

​

下面是我的操作的控制器形式：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.AspNetCore.Mvc.Rendering;
using RazorPagesMovie.Models;

namespace RazorPagesMovie.Pages.Movies
{
    public class CreateModel : PageModel
    {
        private readonly RazorPagesMovie.Models.RazorPagesMovieContext _context;

        public CreateModel(RazorPagesMovie.Models.RazorPagesMovieContext context)
        {
            _context = context;
        }

        public IActionResult OnGet()
        {
            return Page();
        }

        [BindProperty]
        public Movie Movie { get; set; }

        public async Task<IActionResult> OnPostAsync()
        {
            if (!ModelState.IsValid)
            {
                return Page();
            }

            _context.Movie.Add(Movie);
            await _context.SaveChangesAsync();

            return RedirectToPage("./Index");
        }
    }
}

这是我的Create.cshtml：

@page
@model RazorPagesMovie.Pages.Movies.CreateModel

@{
    ViewData["Title"] = "Create";
}

<h1>Create</h1>

<h4>Movie</h4>
<hr />
<div class="row">
    <div class="col-md-4">
        <form method="post">
            <div asp-validation-summary="ModelOnly" class="text-danger"></div>
            <div class="form-group">
                <label asp-for="Movie.Title" class="control-label"></label>
                <input asp-for="Movie.Title" class="form-control" />
                <span asp-validation-for="Movie.Title" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Movie.ReleaseDate" class="control-label"></label>
                <input asp-for="Movie.ReleaseDate" class="form-control" />
                <span asp-validation-for="Movie.ReleaseDate" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Movie.Genre" class="control-label"></label>
                <input asp-for="Movie.Genre" class="form-control" />
                <span asp-validation-for="Movie.Genre" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Movie.Price" class="control-label"></label>
                <input asp-for="Movie.Price" class="form-control" />
                <span asp-validation-for="Movie.Price" class="text-danger"></span>
            </div>
            <div class="form-group">
                <input type="submit" value="Create" class="btn btn-primary" />
            </div>
        </form>
    </div>
</div>

<div>
    <a asp-page="Index">Back to List</a>
</div>

@section Scripts {
    @{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
}

下面是我的文件夹结构：

​

起初我以为可能会有一系列的验证，但实际上在我填写了Release Date和Price之后，我甚至可以在不填写Title和Genre的情况下创建一部电影。因此，这两个字段的验证显然不起作用。

有没有人能分享一些见解？

谢谢!

Answer 1

您的必填字段不能为空，它是空字符串，您必须防止字段被如下所示的空字符串传递：

[StringLength(60, MinimumLength = 3)]
[Required(AllowEmptyStrings =false)]
public string Title { get; set; }

Answer 2

对于必需的字段验证，请使用[BindRequired(ErrorMessage = "Title Required")]修饰函数，而不要使用[Required(ErrorMessage="Title Required")]