微信小程序组件里没有下拉框，正好要用到，记下来以后参考

wxml代码

         
      
        选择接收班级
          
          
            
       
        {
   {grade_name}}
             
           
          
          
            
               
        
         {
   {item}}
              
           
        
     

wxss代码

/* 顶部 */.top{
     width: 100vw;  height: 80rpx;  padding: 0 20rpx;  line-height: 80rpx;  font-size: 34rpx;  border-bottom: 1px solid #000;}.top-text{
     float: left}/* 下拉框 */.top-selected{
       width: 50%;    display: flex;    float: right;    align-items: center;    justify-content: space-between;    border: 1px solid #ccc;    padding: 0 10rpx;    font-size: 30rpx;}/* 下拉内容 */.select_box {
       background-color: #fff;    padding: 0 20rpx;    width: 50%;    float: right;    position: relative;    right: 0;    z-index: 1;    overflow: hidden;    text-align: left;    animation: myfirst 0.5s;    font-size: 30rpx;}.select_one {
       padding-left: 20rpx;    width: 100%;    height: 60rpx;    position: relative;    line-height: 60rpx;    border-bottom: 1px solid #ccc;}/* 下拉过度效果 */@keyframes myfirst {
       from {        height: 0rpx;    }     to {
           height: 210rpx;    }}/* 下拉图标 */.top-selected image{
     height:50rpx;  width:50rpx;  position: absolute;  right: 0rpx;  top: 20rpx;}

js代码

/**   * 页面的初始数据   */  data: {    select:false,    grade_name:'--请选择--',    grades: [        '猛犸机器人1班',        '猛犸机器人2班',        '口才1班',      ]  },/** *  点击下拉框 */  bindShowMsg() {    this.setData({      select: !this.data.select    })  },/** * 已选下拉框 */  mySelect(e) {    console.log(e)    var name = e.currentTarget.dataset.name    this.setData({      grade_name: name,      select: false    })  },

效果