我有两个表Product和Category，并将它们链接在一起，然后我就填写了数据.
I want to select the name of the category for add new item and this name is found in the database When I select the name of category from form I can't get the id this name and storage it in the Product table select category name
当我按下保存显示此错误消息时:
在展示产品中无法显示类别的名称:
我有这些桌子
using System.ComponentModel;
namespace Project.Models.ProjectClasses
{
public class Product
{
public int ProducId { get; set; }
public string? Name { get; set; }
public decimal Price { get; set; }
public int Quantity { get; set; }
public int? IDCategory { get; set; }
public virtual Category? category { get; set; }
public DateTime? Added_Date { get; set; }=DateTime.Now;
}
public class Category
{
public int Id { get; set; }
public string? Name { get; set; }
public virtual ICollection<Product> ?product { get; set; }
}
}
这是ProductController:
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.EntityFrameworkCore;
using Project.ECommerceDbContext;
using Project.Migrations;
using Project.Models.ProjectClasses;
using System.Collections.Specialized;
using System.Linq;
using System.Net.Http.Headers;
namespace Project.Controllers
{
public class ProductsController : Controller
{
private readonly ECommerce _CONTEXT;
public ProductsController(ECommerce CONTEXT)
{
_CONTEXT = CONTEXT;
}
public IActionResult product()
{
IEnumerable<Product> Viewproduct = _CONTEXT.Products.ToList();
return View(Viewproduct);
}
public void Selectecategorywithproduct(int selected = 0)
{
List<Category> category = _CONTEXT.Categories.ToList();
SelectList listItems = new SelectList(category, "Id", "Name", selected);
ViewBag.SelectedList = listItems;
}
public IActionResult Add_Item()
{
Selectecategorywithproduct();
return View();
}
[HttpPost]
[ValidateAntiForgeryToken]
public IActionResult Add_Item(Product Newproduct)
{
if (ModelState.IsValid)
{
var category = _CONTEXT.Categories.Find(Newproduct.IDCategory);
Newproduct.IDCategory = category?.Id;
if (category?.Id != null) // تحقق من وجود الفئة المحددة
{
Console.WriteLine("error");
_CONTEXT.Products.Add(Newproduct);
_CONTEXT.SaveChanges();
TempData["AddNewProduct"] = $"The product {Newproduct.Name} has been added successfully";
return RedirectToAction(nameof(product));
}
else
{
ModelState.AddModelError("IDCategory", "Please select a valid category");
Selectecategorywithproduct();
}
//}
}
return View(Newproduct);
}
}
}
以下是Product.cshtml个视图:
@using Project.Models.ProjectClasses;
@model IEnumerable<Product>
@{
ViewData["Title"] = "product";
}
<h1>product</h1>
<div>
@if (TempData["AddNewProduct"] != null)
{
<div id="addProductMessage" class="alert alert-@TempData["AddNewProduct"]" role="alert" style="color:aquamarine">
@TempData["AddNewProduct"]
</div>
<script>
setTimeout(function () {
$("#addProductMessage").fadeOut("slow", function () {
$(this).remove();
});
}, 3000);
</script>
}
@if (TempData["EditProduct"] != null)
{
<div id="editProductMessage" class="alert alert-@TempData["EditProduct"]" role="alert" style="color:aquamarine">
@TempData["EditProduct"]
</div>
<script>
setTimeout(function () {
$("#editProductMessage").fadeOut("slow", function () {
$(this).remove();
});
}, 3000);
</script>
}
@if (TempData["DeleteProduct"] != null)
{
<div id="deleteProductMessage" class="alert alert-@TempData["DeleteProduct"]" role="alert" style="color:red">
@TempData["DeleteProduct"]
</div>
<script>
setTimeout(function () {
$("#deleteProductMessage").fadeOut("slow", function () {
$(this).remove();
});
}, 3000);
</script>
}
<div class="text-end">
<a asp-controller="Products" asp-action="Add_Item" class="btn btn-success">Add new item</a>
</div>
<table class="table table-hover">
<thead >
<tr class="table-primary">
<th scope="row"></th>
<th>Product Name</th>
<th>Product Categroy</th>
<th>Price</th>
<th>Quantity</th>
<th>Added Date</th>
<th></th>
<th></th>
</tr>
</thead>
<tbody>
@foreach (var product in Model)
{
<tr class="table-light">
<td>@product.ProducId</td>
<td>@product.Name</td>
<td>
@if (product.IDCategory == null||product.IDCategory==0)
{
<span>Not select</span>
}
else
{
@product.category!.Name
}
</td>
<td>$ @product.Price</td>
<td>@product.Quantity</td>
<td>@product.Added_Date</td>
<td>
<a asp-controller="Products" asp-action="Edit_Item" asp-route-id="@product.ProducId" class="btn btn-success"><i class="bi bi-pencil"></i> Edit</a>
<a asp-controller="Products" asp-action="Delete_Item" asp-route-id="@product.ProducId" class="btn btn-danger"><i class="bi bi-trash3"></i> Delete</a>
</td>
<td></td>
</tr>
}
</tbody>
</table>
</div>
以下是Add_item.cshtml人的观点:
@using Project.Models.ProjectClasses;
@model Product
@{
ViewData["Title"] = "Add Item";
}
<h1>Add Item</h1>
<form method="post">
<fieldset>
<div class="form-group">
<label asp-for="Name" class="form-label mt-4">Product Name</label>
<input class="form-control" asp-for="Name" placeholder="Enter Product Name">
<span asp-validation-for="Name" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="Price" class="form-label mt-4">Price</label>
<input class="form-control" asp-for="Price" placeholder="Price">
<span asp-validation-for="Price" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="Quantity" class="form-label mt-4">Quantity</label>
<input class="form-control" asp-for="Quantity" placeholder="Quantity">
<span asp-validation-for="Quantity" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="IDCategory" class="form-label mt-4">Category ID</label>
<select class="form-control" asp-items="ViewBag.SelectedList">
<option value="0">Selecte Category</option>
</select>
<input type="hidden" id="IDCategoryHidden" name="IDCategoryHidden" value="" />
<span asp-validation-for="IDCategory" class="text-danger"></span>
</div>
<p></p>
<button type="submit" class="btn btn-primary"><i class="bi bi-check2-all"></i> Save</button>
<a asp-controller="Products" asp-action="product" class="btn "><i class="bi bi-backspace"></i> Go Back</a>
</fieldset>
</form>
@section Scripts
{
<partial name="_ValidationScriptsPartial" />
}
拜托，我想解决这个问题
