htmldiv classlayui-form-item label classlayui-form-label所属国家/label div classlayui-input-inline asp:DropDownList IDddlarea lay-verifyrequired runatserver AutoPostBacktrue OnSelectedIndexChangedddlarea_SelectedIndexChanged lay-filterarea/asp:DropDownList/div /divjsvar form layui.form; form.on(select(area), function(data){ // ... 前端处理 / AJAX 填充等 ... // 触发服务器端 SelectedIndexChanged __doPostBack(% ddlarea.UniqueID %, ); });