TempData is always 0

Question

关于我正在编写的web应用程序的背景。我有一个创建产品的剃刀页面(信息被插入数据库，数据库正在创建产品Id(。之后，在帖子请求中，我想重定向到另一个显示该产品所有信息的页面剃刀。

我试图使用TempData传递产品Id，但由于某种原因，它总是0。我想指出的是，我对MVC和ASP.NET核心还相当陌生。我知道我可能需要创建一个控制器来传递数据，但我不确定。以下是我的代码：

CreateProduct.cshthml.cs:

using Accounts.Data;
using Accounts.Domain;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
namespace Template_Site.Pages
{
public class CreateProductModel : PageModel
{
private readonly IProductRepository _products;
[TempData]
public int productId { get; set; }
[BindProperty]
public Product Product { get; set; }
public CreateProductModel(IProductRepository product)
{
_products=product;
}
public IActionResult OnGet()
{
return Page();
}

public IActionResult OnPost()
{
if (ModelState.IsValid)
{
//_products.AddProduct(Product);
//_products.SaveAll();
productId = _products.RecentProduct().Id;
return RedirectToPage("/ProductReDirect", productId);
}
return Page();
}
}
}

CreateProduct.cshthml:

@page
@model Template_Site.Pages.CreateProductModel
@{
}
<div class="header">
<h1>Product Creation</h1>
</div>
<div class="row">
<form method ="post">
<div class="column side"></div>
<div class= "column middle">
<div class="ForForm">
<label asp-for=@Model.Product.Name></label>
<input asp-for=@Model.Product.Name class="form-contorl"/>
<span class="text-danger" asp-validation-for=@Model.Product.Name></span>
</div>
<div class="ForForm">
<label  asp-for=@Model.Product.Version></label>
<input  asp-for=@Model.Product.Version class="form-contorl"/>
<span class="text-danger" asp-validation-for=@Model.Product.Version></span>
</div>
<div class="ForForm" >
<label asp-for=@Model.Product.Amount></label>
<input asp-for=@Model.Product.Amount class="form-contorl"/>
<span class="text-danger" asp-validation-for=@Model.Product.Amount></span>
</div>
<div>
<button type="submit" class= "button button3" asp-page="/ProductReDirect" asp-route-productId=@Model.productId>Create</button>
</div>
</div>
<div class="column side"></div>
</form>
</div>

ProductReDirect.cshtml.cs:

using Accounts.Data;
using Accounts.Domain;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
namespace Template_Site.Pages
{
public class ProductReDirectModel : PageModel
{
private readonly IProductRepository _product;
public Product Product { get; set; }
[BindProperty(SupportsGet = true)]
public int productId { get; set; }
public ProductReDirectModel(IProductRepository product)
{
_product = product;
}
public void OnGet()
{
productId = (int)TempData["productId"];
TempData.Keep("productId");
Product = new Product();
Product = _product.GetById(productId);
}
}
}

ProductReDirect.csthml:

@page
@model Template_Site.Pages.ProductReDirectModel
@{
}
<h2>You created a new product!</h2>
<h2> id: @Model.productId</h2>

Answer 1

首先，您需要删除按钮中的asp-page和asp-route-productId，否则您将无法转到CreateProduct.cshtml.cs:中的OnPost处理程序

CreateProduct.cshthml:

@page
@model Template_Site.Pages.CreateProductModel
@{
}
<div class="header">
<h1>Product Creation</h1>
</div>
<div class="row">
<form method ="post">
<div class="column side"></div>
<div class= "column middle">
<div class="ForForm">
<label asp-for=@Model.Product.Name></label>
<input asp-for=@Model.Product.Name class="form-contorl"/>
<span class="text-danger" asp-validation-for=@Model.Product.Name></span>
</div>
<div class="ForForm">
<label  asp-for=@Model.Product.Version></label>
<input  asp-for=@Model.Product.Version class="form-contorl"/>
<span class="text-danger" asp-validation-for=@Model.Product.Version></span>
</div>
<div class="ForForm" >
<label asp-for=@Model.Product.Amount></label>
<input asp-for=@Model.Product.Amount class="form-contorl"/>
<span class="text-danger" asp-validation-for=@Model.Product.Amount></span>
</div>
<div>
<button type="submit" class= "button button3" >Create</button>
</div>
</div>
<div class="column side"></div>
</form>
</div>

然后你需要在OnPost处理程序中传递productId，如下所示：

public IActionResult OnPost()
{
if (ModelState.IsValid)
{
//_products.AddProduct(Product);
//_products.SaveAll();
productId = _products.RecentProduct().Id;
return RedirectToPage("/ProductReDirect",new { productId = productId });
}
return Page();
}
}

并删除ProductReDirect.cshtml.cs:中的productId = (int)TempData["productId"];

public void OnGet()
{
Product = new Product();
Product = _product.GetById(productId);
}