c# - 将默认值设置为选择列表

Question

我有这个字符串列表：

public static readonly List<string> LIST_ITEM_STATE = new List<string>
{
    "Brand new",
    "Never used",
    "Slightly used",
    "Used",
    "Heavily used",
    "Damaged",
    "Ruined",
    "Run for your life"
};

我正在以这种方式在课堂上构建一个选择列表：

public string mItemState { get; set; }
public IEnumerable<SelectListItem> mItemStateList { get; set; }

mItemStateList = new SelectList(ValueDomain.LIST_ITEM_STATE);

而且，在我看来，我像这样渲染下拉列表：

Item State: @Html.DropDownListFor(_item => _item.mItemState, Model.mItemStateList, String.Empty)

下拉列表就像一个魅力，但我一直在寻找在Brand New保留String.Emtpty选项的同时通过默认设置选定值的方法。我怎么能那样做？

Answer 1

我认为你必须这样做：

public static readonly List<string> LIST_ITEM_STATE = new List<string>
{
    string.Empty,
    "Brand new",
    "Never used",
    "Slightly used",
    "Used",
    "Heavily used",
    "Damaged",
    "Ruined",
    "Run for your life"
};

并在 中设置选定的值SelectList：

 mItemStateList = new SelectList(ValueDomain.LIST_ITEM_STATE, "Brand new");

或者确保属性的值设置为您想要的初始值：

_item.mItemState = "Brand new";

Answer 2

像这样定义您的 SelectList：

mItemStateList = new SelectList(ValueDomain.LIST_ITEM_STATE, mItemState);