asp.net-mvc-3 - 如何访问保存在 session 中的列表内的对象。 ASP.NET MVC 3

Question

所以我有这个代码:

var list = new List<Carrito> { 
                new Carrito { ProductId = producto.ID , Cantidad = 1, PrecioUnitario = producto.Precio }
            };

            Session["list"] = list;

            return View();

然后我加载 View ，但我不知道如何打印 session 内的内容。有什么想法吗？

这是我在 View 中使用的代码，但不起作用:

@foreach(var item in (IEnumerable<object>)Session["list"] )
{
  <p>@item.ProductId</p>
}

Answer 1

这就像从 session 变量中读回值并将其转换为原始类型一样简单，然后做任何你想做的事情

示例:

@{
    if(Session["list"]!= null)
    {
    var listBackFromSession = (List<Carrito>)Session["list"];
    // do what you want
    }
 }

我的建议是使用更优雅的ViewBag方式。

来自asp.net mvc官方网站关于Viewbag的引用:

New "ViewBag" Property

MVC 2 controllers support a ViewData property that enables you to pass data to a view template using a late-bound dictionary API. In MVC 3, you can also use somewhat simpler syntax with the ViewBag property to accomplish the same purpose. For example, instead of writing ViewData["Message"]="text", you can write ViewBag.Message="text". You do not need to define any strongly-typed classes to use the ViewBag property. Because it is a dynamic property, you can instead just get or set properties and it will resolve them dynamically at run time. Internally, ViewBag properties are stored as name/value pairs in the ViewData dictionary. (Note: in most pre-release versions of MVC 3, the ViewBag property was named the ViewModel property.)

此外，这是一篇关于 MVC 中保存数据的不同方法的好文章:http://rachelappel.com/when-to-use-viewbag-viewdata-or-tempdata-in-asp.net-mvc-3-applications

示例:

var list = new List<Carrito> { 
                new Carrito { ProductId = producto.ID , Cantidad = 1, PrecioUnitario = producto.Precio }
            };

// use ViewBag
ViewBag.myList = list;

then inside your view, read them back like this:

var myList = (List<Carrito>)ViewBag.myList;
// your code