难道不能使用流畅的语法更简洁地重写吗？

Question

public static class ListOfT
{

    public static List<SelectListItem> ToSelectList<T>(this List<T> value, 
                                                       Func<T, string> getText, 
                                                       Func<T, string> getValue, 
                                                       string selectedValue)
    {
        List<SelectListItem> items = new List<SelectListItem>();

        foreach (var item in value)
        {
            items.Add(new SelectListItem
            {
                Text = getText(item),
                Value = getValue(item),
                Selected = selectedValue == getValue(item) 
            });
        }

        return items
            .OrderBy(l => l.Text)
            .ToList();
    }
}

样本用法：

[HttpGet]
public ActionResult Create()
{

    List<State> states = new List<State>() { new State {Name = "Michigan", StateCode = "MI" },
                                             new State {Name = "Connecticut", StateCode = "CT" }};

    StateAssessmentCreateViewModel stateAssessmentViewModel = new StateAssessmentCreateViewModel();
    stateAssessmentViewModel.States = states.ToSelectList(state => state.Name, state => state.StateCode, "CT"); 

    return View(stateAssessmentViewModel);
}

查看：

@Html.DropDownListFor(model => model.StateCode, Model.States, "-- None -- ", new { htmlAttributes = new { @class = "form-control" })

我认为我在视图中的语法错误，因为formcontrol类属性格式不正确。但请注意确定原因。

 <div class="form-group">
            <label class="control-label col-md-2" for="StateCode">State</label>
            <div class="col-md-10">
                <select htmlAttributes="{ class = form-control }" id="StateCode" name="StateCode"><option value="">-- None -- </option>
                                        <option selected="selected" value="CT">Connecticut</option>
                                    <option value="MI">Michigan</option>
                        </select>
                <span class="field-validation-valid text-danger" data-valmsg-for="CancelDate" data-valmsg-replace="true"></span>
            </div>
        </div>
.

Answer 1

您的项目包含Select：

public static List<SelectListItem> ToSelectList<T>(this List<T> source,
                                                   Func<T, string> getText,
                                                   Func<T, string> getValue,
                                                   string selectedValue)
{
    return source
        .Select(x => new SelectListItem
        {
            Text = getText(x),
            Value = getValue(x),
            Selected = selectedValue == getValue(x)
        })
        .ToList();
}