利用js获取下拉框中所选的值

现在的需求是：下拉框中要是选择加盟商让其继续选择学校，要是选择平台管理员则不需要选择学校。隐藏选择下拉列表。

选择枚举值：

/// <summary>
/// 平台角色
/// </summary>
public enum AdministratorRole
{
[Display(Name = "平台管理员")]
PlatformAdministrator = 1,
[Display(Name = "加盟商")]
JoiningTrader = 10
}

代码：

<div class="form-group">
 @Html.LabelFor(x => x.AdministratorRole, new { @class = "col-sm-2 control-label" })
 <div class="col-sm-8">
  @Html.EnumDropDownListFor(x => x.AdministratorRole, new { @class = "form-control", onChange = "showSchool(this.value)", placeholder = Html.DisplayNameFor(x => x.AdministratorRole) })
 </div>
 <div class="col-sm-2">
  <div class="help-block">@Html.ValidationMessageFor(x => x.AdministratorRole)</div>
 </div>
</div>
<div class="form-group" style="display:none" id="schoolSelect">
 @Html.LabelFor(x => x.SchoolId, new { @class = "col-sm-2 control-label" })
 <div class="col-sm-8">
  @Html.DropDownListFor(x => x.SchoolId, Model.Schools, new { @class = "form-control", placeholder = Html.DisplayNameFor(x => x.SchoolId) })
 </div>
 <div class="col-sm-2">
  <div class="help-block">@Html.ValidationMessageFor(x => x.SchoolId)</div>
 </div>
</div>

    先让学校列表隐藏，style=”display:none”;效果和下图一样。我们利用下拉框的onChange事件来让其执行设定的方法showSchool(),这里面的参数是我们选择的值，this代表的AdministratorRole。

js代码：

<script type="text/javascript">
function showSchool(v){  
 if (10 == v) {
  document.getElementById("schoolSelect").style = "display:inline";
 } else {
  document.getElementById("schoolSelect").style = "display:none";
 }
}
</script>

这样就可以了。

效果：

来源：http://www.cnblogs.com/netxiaohui/p/5859958.html