問題與ModelBinding從我的控制器類

Question

方法

public RedirectToRouteResult AddToCart(Cart cart, int productID, string returnUrl) 
      { 
       Product product = productsRepository.Products.FirstOrDefault(p => p.ProductID == productID); 
       cart.AddItem(product, 1); 
       return RedirectToAction("Index", new { returnUrl }); 
      } 

public ViewResult Index(Cart cart, string returnUrl) 
     { 
      ViewData["returnUrl"] = returnUrl; 
      ViewData["CurrentCategory"] = "Cart"; 
      return View(cart); 
     } 

我還實施了ModelBinder的如下：

public class CartModelBinder : IModelBinder 
{ 
    private const string cartSessionKey = "_cart"; 

    #region IModelBinder Members 

    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) 
    { 
     if (bindingContext.Model != null) 
      throw new InvalidOperationException("Cannot update instances"); 
     Cart cart = (Cart)controllerContext.HttpContext.Session[cartSessionKey]; 
     if (cart == null) 
     { 
      cart = new Cart(); 
      controllerContext.HttpContext.Session["cartSessionKey"] = cart; 
     } 
     return cart; 
    } 
    #endregion 
} 

我沒有得到車信息到我的索引視圖，以便它顯示我的購物車爲空。不知道發生了什麼問題，但我絕對沒有在索引操作方法中看到購物車。

而且，我的觀點是

<content name="TitleContent"> 
    SportsStore: Your Cart 
</content> 
<content name="MainContent"> 
    <viewdata model="DomainModel.Entities.Cart"/> 
    <h2>Your Cart</h2> 
    <table width="90%" align="center"> 
     <thead><tr> 
      <th align="center">Quantity</th> 
      <th align="center">Item</th> 
      <th align="center">Price</th> 
      <th align="center">SubTotal</th> 
     </tr></thead> 
     <tbody> 
     <for each = "var line in Model.Lines" >    
      <tr> 
       <td align="center">${line.Quantity}</td> 
       <td align="left">${line.Product.Name}</td> 
       <td align="right">${line.Product.Price.ToString("c")}</td> 
       <td align="right">${(line.Quantity * line.Product.Price).ToString("c")}</td> 
      </tr>   
     </for> 
     </tbody> 
     <tfoot><tr> 
      <td colspan="3" align="right">Total:</td> 
      <td align="right"> 
       ${Model.ComputeTotalValue().ToString("c")} 
      </td> 
     </tr></tfoot> 
    </table> 
    <p align="center" class="actionButtons"/> 
     <a href="${Html.Encode(ViewData["returnUrl"])}">Continue Shopping</a> 
    </p> 
</content> 

Answer 1

RedirectToAction不傳遞任何信息。它只會執行常規的HTTP重定向。

爲什麼不這樣做：

public ViewResult AddToCart(Cart cart, int productID, string returnUrl) 
{ 
     Product product = productsRepository.Products 
            .FirstOrDefault(p => p.ProductID == productID); 
     cart.AddItem(product, 1); 

     ViewData["returnUrl"] = returnUrl; 
     ViewData["CurrentCategory"] = "Cart"; 
     return View("Index", cart); 
}