无法将 lambda 表达式转换为类型 'IEnumerable<SelectListItem>'，因为它不是委托类型

Question

视图模型

public class EmployeeIndexViewModel {
    public int selectedDepartment { get; set; }
    public IList departments1 { get; set; }
}

控制器操作

List<Department> list = new List<Department>();
list.Add(new Department { ID = 1, Name = "D1" });
list.Add(new Department { ID = 2, Name = "D2" });
list.Add(new Department { ID = 3, Name = "D3" });
employeeIndexViewModel.departments1 = list;
employeeIndexViewModel.selectedDepartment = "2";

查看

@Html.DropDownListFor(m => m.department, new SelectList(Model.departments1, "Id", "Name"))

现在，编码工作正常。但是我不喜欢这首曲子

new SelectList(Model.departments1, "Id", "Name")

我想将它添加到我的视图模型中，然后将它绑定到我的视图中。所以我改变了我的 ViewModel

新视图模型

public class EmployeeIndexViewModel {
    public int selectedDepartment { get; set; }
    public IList departments1 { get; set; }
    public IEnumerable<SelectListItem> departments2 { get; set; }//add this
}

新控制器动作

List<Department> list = new List<Department>();
list.Add(new Department { ID = 1, Name = "D1" });
list.Add(new Department { ID = 2, Name = "D2" });
list.Add(new Department { ID = 3, Name = "D3" });
employeeIndexViewModel.departments1 = list;
employeeIndexViewModel.selectedDepartment = "2";
employeeIndex2ViewModel.departments2 = new SelectList(list, "id", "name");// add this

新视图

@Html.DropDownListFor(m => m.department, new SelectList(Model.departments1, "Id", "Name"))
@Html.DropDownListFor(m => m.department, (SelectList)(m => m.departments2))//add this

我收到这个错误：

Cannot convert lambda expression to type 'IEnumerable<SelectListItem>' because it is not a delegate type

Answer 1

删除新视图中的 lambda 表达式 (SelectList)(m => m.departments2) 并替换为 Model.departments2

无法将 lambda 表达式转换为类型 'IEnumerable<SelectListItem>'，因为它不是委托类型

Cannot convert lambda expression to type 'IEnumerable<SelectListItem>' because it is not a delegate type

asp.net-mvc

dropdownlistfor