asp.net-mvc-3 - 不绑定(bind)到模型属性 mvc3 的下拉列表

Question

MVC3 DropdownListFor 不将模型属性绑定(bind)到选定值这是我的观点

@{var items = new List<SelectListItem>(){
                            new SelectListItem {Text = "2", Value = "2", Selected = true},
                            new SelectListItem {Text = "3", Value = "3", Selected = false},
                            new SelectListItem {Text = "4", Value = "4", Selected = false},
                            new SelectListItem {Text = "5", Value = "5", Selected = false}
                        };

        }   
@Html.DropDownListFor(x => x.InvoiceItem.Count, new SelectList(items, "Value", "Text"))

InvoiceModel 有一个名为 InvoiceItem 类的属性，该类还有一个 int 类型的属性 Count。count 属性始终为 0，并且不会更新为从下拉列表中选择的值。

请帮助我已经花了几个小时在这上面。谢谢。

---

感谢您的回复。但我仍然有问题。

我用过@Html.DropDownListFor(x => x.InvoiceItem.Count, new SelectList(items, "value", "text", 2))

还尝试了@Html.DropDownListFor(x => x.InvoiceItem.Count, new SelectList(items, "value", "text", "2"))

Count 属性始终为 0。我在这里缺少什么。

Answer 1

使用:

new SelectList(items, "value", "text", selectedvalue);

例如:

@{var items = new List<SelectListItem>(){
                                new SelectListItem {Text = "2", Value = "2"},
                                new SelectListItem {Text = "3", Value = "3"},
                                new SelectListItem {Text = "4", Value = "4"},
                                new SelectListItem {Text = "5", Value = "5"}
                            };

            }   
    @Html.DropDownListFor(x => x.InvoiceItem.Count, new SelectList(items, "Value", "Text", 2))