项目场景：
主要用于为民族select下拉框动态生成option值，同时在实现编辑功能时，表单中的select下拉框的选中项为后台传过来的数据。
举例：
如下图所示的表单内容，下图的民族和政治面貌select下拉框分别采用了不同的方法来实现设置选中项。
代码：
民族的select下拉框的实现代码（动态添加option项同时设置下拉框的选中项）
jsp
<div class="layui-inline"><label class="layui-form-label">民族</label><div class="layui-input-inline"><select id="edit_nation" class="layui-input"placeholder="请输入民族" name="nation"></select></div></div>
还有下面这个只能写在jsp页面
<script>var stu = "<%=request.getAttribute("sn") %>"</script>
js
//获取民族列表外加设置select初始值$.ajax({url:'/getNation.action',dtatType:'json',async:true,success:function (data) {//第一个添加的为选中值//console.log(stu)$('#edit_nation').append(new Option(stu,stu));$.each(data,function(index,item){if(item.text!=stu){$('#edit_nation').append(new Option(item.text,item.id));//继续往下拉菜单里添加元素}})form.render('select');//这个一定要有}})
controller
@RequestMapping(value="/getNation.action")@ResponseBodypublic List<ComboboxModel> getnation(){String[] item ={"汉族","蒙古族","回族","藏族","维吾尔族","苗族","彝族","壮族","布依族","朝鲜族","满族","侗族","瑶族","白族","土家族", "哈尼族","哈萨克族","傣族","黎族","傈僳族","佤族","畲族","高山族","拉祜族","水族","东乡族","纳西族","景颇族","柯尔克孜族", "土族","达斡尔族","仫佬族","羌族","布朗族","撒拉族","毛南族","仡佬族","锡伯族","阿昌族","普米族","塔吉克族","怒族", "乌孜别克族", "俄罗斯族","鄂温克族","德昂族","保安族","裕固族","京族","塔塔尔族","独龙族","鄂伦春族","赫哲族","门巴族","珞巴族","基诺族"};List<ComboboxModel> models=new ArrayList<>();for (int i=0;i<item.length;i++) {models.add(new ComboboxModel(item[i],item[i]));}return models;}
下面这个是获取需要修改的学生的基本信息传到表单
@RequestMapping(value = "/editStudent.action")public String editStudent(HttpServletRequest req, @RequestParam("sid") String sid) {Studentinfo student = studentService.findStudentById(sid);System.out.println(student);req.setAttribute("s", student);req.setAttribute("sn", student.getNation());//!!!注意return "/StudentView/editStudent";}
接下来这个方法比较简单，但是仅适用option项的数量固定且比较少，仅需要修改jsp内容（原本下拉选择中内容因为涉及zhengzhi内容，被打回修改了一下，我用“水果”来代替了这部分内容）
<div class="layui-inline"><label class="layui-form-label">你喜爱的水果：</label><div class="layui-input-inline"><select id="edit_spolitics" class="layui-input" placeholder="请选择水果" name="spolitics"><c:if test="${s.spolitics!='苹果'}"><option value="苹果">苹果</option></c:if><c:if test="${s.spolitics!='香蕉'}"><option value="香蕉">香蕉</option></c:if><c:if test="${s.spolitics!='菠萝'}"><option value="菠萝">菠萝</option></c:if><c:if test="${s.spolitics!='火龙果'}"><option value="火龙果">火龙果</option></c:if><c:if test="${s.spolitics!='榴莲'}"><option value="榴莲">榴莲</option></c:if><c:if test="${s.spolitics!='其他'}"><option value="其他">其他</option></c:if><option value="${s.spolitics}" selected>${s.spolitics}</option></select></div>
over
