Html.DropDownList()的用法

页面代码如下：

<%= Html.DropDownList("Category", ViewData["Categories"] as SelectList,"--请选择--",new { @class = "my-select-css-class" } )%>

Controllers代码：

public ActionResult Create() 

{
        List<Category> categories = categoryService.GetAll();
        ViewData["Categories"] = new SelectList(categories, "Id", "Name");
        return View();
}