利用js取到下拉框中选择的值

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：