Html.EnumDropdownListFor：显示默认文本

在我看来我有一个枚举下拉列表 http://www.asp.net/mvc/overview/releases/mvc51-release-notes#Enum（Asp.Net MVC 5.1 中的新功能）。

@Html.EnumDropDownListFor(m => m.SelectedLicense,new { @class="form-control"})

如果我执行上面的代码，我会得到以下枚举的下拉列表。

public enum LicenseTypes
{
    Trial = 0,
    Paid = 1
}

但默认情况下我希望我的下拉列表有一个值（自定义文本） 这就是我尝试过的

@Html.EnumDropDownListFor(m => m.SelectedLicense,"Select a license" ,new { @class="form-control"})

but now the problem is when i run it, my dropdownlist looks like this So, the default text I want to show doesn't appear by default. If a user selects "select a license" and tries to submit the form, it does show an error saying "select a license" but it doesn't show as default text. Something i need to change?

PS：图片为页面加载时的截图。默认情况下，它将显示“试用”作为选定选项。

尝试改变Index of LicenseTypes从...开始1 not 0像下面这样：

public enum LicenseTypes
{
    Trial = 1,
    Paid = 2
}

然后你可以使用Range attribute验证所选的许可证类型，如下所示：

public class YourViewModel
{
     //Other properties
     [Range(1,int.MaxValue,ErrorMessage = "Select a correct license")]
     public LicenseTypes LicenseTypes { get; set; }
}

最后，在您看来：

   @Html.EnumDropDownListFor(m => m.LicenseTypes,"Select a license",new { @class = "form-control"})
   @Html.ValidationMessageFor(m => m.LicenseTypes)