脚手架 Razor 创建页面不添加项目

Question

我通过脚手架为以下模型创建了一个“创建”剃刀页面：

public class Product
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int ProdId { get; set; }
    [Required]
    public string ProdName { get; set; }
    [Required]  
    public float Price { get; set; }

    [Required]
    [ForeignKey("Category")]
    public int CategoryID { get; set; }

    [Required]
    [ForeignKey("Supplier")]
    public int SupplierID { get; set; }

    
    public virtual Category category { get; set; }
    
    public virtual Supplier supplier { get; set; }


    public List<Review> reviews { get; set; }

    public List<ShoppingCart> shoppingCarts { get; set; }

    public List<Order> orders { get; set; }

}

创建了以下剃刀页面：

@page
@model WebStore.Pages.Products.CreateModel
@using Microsoft.AspNetCore.Mvc.ViewEngines
@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers
@{
    ViewData["Title"] = "Create";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h1>Create</h1>

<h4>Product</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="Product.ProdName" class="control-label"></label>
                <input asp-for="Product.ProdName" class="form-control" />
                <span asp-validation-for="Product.ProdName" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Product.Price" class="control-label"></label>
                <input asp-for="Product.Price" class="form-control" />
                <span asp-validation-for="Product.Price" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Product.CategoryID" class="control-label"></label>
                <select asp-for="Product.CategoryID" class ="form-control" asp-items="ViewBag.CategoryID"></select>
            </div>
            <div class="form-group">
                <label asp-for="Product.SupplierID" class="control-label"></label>
                <select asp-for="Product.SupplierID" class ="form-control" asp-items="ViewBag.SupplierID"></select>
            </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");}
}

使用以下create.cs相关文件：

public class CreateModel : PageModel
{
    private readonly WebStore.MyDbContext _context;

    public CreateModel(WebStore.MyDbContext context)
    {
        _context = context;
    }

    public IActionResult OnGet()
    {
    ViewData["CategoryID"] = new SelectList(_context.Categories, "CatId", "CatDescription");
    ViewData["SupplierID"] = new SelectList(_context.Suppliers, "supplierId", "supplierId");
        return Page();
    }

    [BindProperty]
    public Product Product { get; set; } = default!;
    

    // To protect from overposting attacks, see https://aka.ms/RazorPagesCRUD
    public async Task<IActionResult> OnPostAsync()
    {
      if (!ModelState.IsValid || _context.Products == null || Product == null)
        {
            return Page();
        }

        _context.Products.Add(Product);
        await _context.SaveChangesAsync();

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

我面临的问题是，当我尝试添加另一个项目并单击“创建”时，实际上没有添加任何项目，数据库中没有任何更改，也没有重定向到索引。

CategoryID和supplierID引用其他实体。

Answer 1

可以调试页面吗？我相信您的 _context （您是否注册了 DbContext）或您的产品为空或 ModelState 无效。在这种情况下，页面将在将产品保存到数据库之前返回。