@ Html.DropDownList（）占位符禁用和选择

Question

如果我用静态值占位符，然后可以创建作为第一选项@Html.DropDownList()，它可以应用禁用，并在此选项选择的属性这样

@Html.DropDownList("month", new List<SelectListItem> 
{ 
    new SelectListItem{ Text="Select Month", Value = "0" , Disabled = true, Selected = true}, 
    new SelectListItem{ Text="January", Value = "1" }, 
    new SelectListItem{ Text="February", Value = "2" }, 
    new SelectListItem{ Text="March", Value = "3" }, 
    new SelectListItem{ Text="April", Value = "4" }, 
    new SelectListItem{ Text="May", Value = "5" }, 
    new SelectListItem{ Text="June", Value = "6" }, 
    new SelectListItem{ Text="July", Value = "7" }, 
    new SelectListItem{ Text="August", Value = "8" }, 
    new SelectListItem{ Text="September", Value = "9" }, 
    new SelectListItem{ Text="October", Value = "10" }, 
    new SelectListItem{ Text="November", Value = "11" }, 
    new SelectListItem{ Text="December", Value = "12" }, 
}, new {@class = "form-control"}) 

但如果我创建下拉列表就像一个号码范围，并作出这样的占位符：

@Html.DropDownList("year", 
     Enumerable.Range(1900, 200) 
      .Select(i => new SelectListItem { Text = i.ToString(), Value = i.ToString() }), 
     "Please Select Year", new { @class = "form-control" }) 

是否有可能使这个Please Select Year禁用和选中的？

Answer 1

注意您使用的是year降下来过载使您的默认项外观上没有控制权。

但是你能恢复到你正在使用几个月同样的方法，用的代码一点点：

@{ 
    var years = new List<SelectListItem>{ 
     new SelectListItem{ Text="Select Year", Value = "0" , Disabled = true, Selected = true}, 
    }; 

    years.AddRange(Enumerable.Range(1900, 200) 
      .Select(i => new SelectListItem { Text = i.ToString(), Value = i.ToString() })); 
} 

@Html.DropDownList("year", 
     years, 
     new { @class = "form-control" })