1

我的语法在我的控制器内创建一个月内几天的选择列表时遇到了一些问题。我得到了几个月和几年的工作，但是 for 循环给我带来了一些麻烦。

Visual Studio 给我的错误是：“Invalid initializer member declarator”和“名称 Days 在当前上下文中不存在。”

视图模型

public class DateSearchViewModel
{
    public int SelectedMonth { get; set; }
    public IEnumerable<SelectListItem> Months { get; set; }
    public int SelectedDay { get; set; }
    public IEnumerable<SelectListItem> Days { get; set; }
    public int SelectedYear { get; set; }
    public IEnumerable<SelectListItem> Years { get; set; }
}

控制器

    [ChildActionOnly]
    public ActionResult _Header()
    {
        var DateVM = new DateSearchViewModel
        {
            //Set selected value of month.
            SelectedMonth = 5,
            Months = new List<SelectListItem> 
            {
                new SelectListItem {Text = "Jan", Value = "1"},
                new SelectListItem {Text = "Feb", Value = "2"},
                new SelectListItem {Text = "Mar", Value = "3"},
                new SelectListItem {Text = "Apr", Value = "4"},
                new SelectListItem {Text = "May", Value = "5"},
                new SelectListItem {Text = "Jun", Value = "6"},
                new SelectListItem {Text = "Jul", Value = "7"},
                new SelectListItem {Text = "Aug", Value = "8"},
                new SelectListItem {Text = "Sep", Value = "9"},
                new SelectListItem {Text = "Oct", Value = "10"},
                new SelectListItem {Text = "Nov", Value = "11"},
                new SelectListItem {Text = "Dec", Value = "12"},
            },

            //Set selected value of Day.
            SelectedDay = 13,
            Days = new List<SelectListItem>
            {
                for (var i = 1; i <= 31; i++)
                {
                    Days.Add(new SelectListItem { Text = i.ToString(), Value = i.ToString()});
                }
            },

            //Set selected value of Year.
            SelectedYear = 2010,
            Years = new List<SelectListItem> 
            {
                new SelectListItem {Text = "2009", Value = "2009"},
                new SelectListItem {Text = "2010", Value = "2010"},
                new SelectListItem {Text = "2011", Value = "2011"},
                new SelectListItem {Text = "2012", Value = "2012"},
            }
        };

        return PartialView(DateVM);
    }

视图模型：

@Html.DropDownListFor(x => x.SelectedMonth, Model.Months) / @Html.DropDownListFor(x => x.SelectedDay, Model.Days) / @Html.DropDownListFor(x => x.SelectedYear, Model.Years)
4

2 回答 2

3

正如编译器试图告诉你的那样，你不能这样做。
初始化器只能包含表达式。

相反，您可以使用 LINQ：

Days = Enumerable.Range(1, 31)
                 .Select(i => new SelectListItem { Text = i.ToString() }))
于 2012-04-17T17:54:35.813 回答
2

您不能在初始化程序中放置循环：

Days = new List<SelectListItem>
{
    for (var i = 1; i <= 31; i++)
    {
        Days.Add(new SelectListItem { Text = i.ToString(), Value = i.ToString()});
    }
},

因此，只需实例化它并稍后使用循环：

var DateVM = new DateSearchViewModel 
{
    ...
    Days = new List<SelectListItem>(),
    ...
}

for (var i = 1; i <= 31; i++)
{
    DateVM.Days.Add(new SelectListItem { Text = i.ToString(), Value = i.ToString()});
}
于 2012-04-17T17:52:51.333 回答