微信小程序下拉框组件

》》下拉组件

1.组件结构：

2.index.js：

 //index.js
 Component({
   /**
    * 组件的属性列表
    */
   properties: {
     propArray: {
       type: Array,
     }
   },
   /**
    * 组件的初始数据
    */
   data: {
     selectShow: false,//初始option不显示
     selectText: "请选择",//初始内容
   },
   /**
    * 组件的方法列表
    */
   methods: {
     //option的显示与否
     selectToggle: function () {
       var nowShow = this.data.selectShow;//获取当前option显示的状态

       this.setData({
         selectShow: !nowShow
       })
     },
     //设置内容
     setText: function (e) {
       var nowData = this.properties.propArray;//当前option的数据是引入组件的页面传过来的，所以这里获取数据只有通过this.properties
       var nowIdx = e.target.dataset.index;//当前点击的索引
       var nowText = nowData[nowIdx].text || nowData[nowIdx].value || nowData[nowIdx];//当前点击的内容
       //再次执行动画，注意这里一定，一定，一定是this.animation来使用动画
       this.setData({
         selectShow: false,
         selectText: nowText,
       })
       this.triggerEvent('select', nowData[nowIdx])
     }
   }
 })

3.index.json:

 {
   "component": true,
   "usingComponents": {}
 }

4.index.wxml:

 <view class='ms-content-box'>
     <view class='ms-content' bindtap='selectToggle'>
         <view class='ms-text'>{{selectText}}</view>
          <view class="{{selectShow ? 'icon-up' : 'icon-down'}}"></view>
     </view>
     <view class='ms-options' wx:if="{{selectShow}}">
         <view wx:for="{{propArray}}" data-index="{{index}}" wx:key='index' class='ms-option' bindtap='setText'>{{item.text || item.value || item}}</view>
     </view>
 </view>

5.index.wxss:

 /* components/single-dropdown-select/index.wxss */

 .ms-content-box {
   width: 120px;
 }

 .ms-content {
   border: 1px solid #e2e2e2;
   background: white;
   font-size: 16px;
   position: relative;
   height: 30px;
   line-height: 30px;
 }

 .ms-text {
   overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;
   padding: 0 40px 0 6px;
   font-size: 14px;
 }

 .ms-options {
   background: white;
   width: inherit;
   position: absolute;
   border: 1px solid #e2e2e2;
   border-top: none;
   box-sizing: border-box;
   z-index:;
   max-height: 120px;
   overflow: auto;
 }

 .ms-option {
   height: 30px;
   line-height: 30px;
   border-top: 1px solid #e2e2e2;
   padding: 0 6px;
   text-align: left;
   overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;
   font-size: 14px;
 }

 .ms-item:first-child {
   border-top: none;
 }

 .icon-right, .icon-down, .icon-up {
   display: inline-block;
   padding-right: 13rpx;
   position: absolute;
   right: 20rpx;
   top: 10rpx;
 }

 .icon-right::after, .icon-down::after, .icon-up::after {
   content: "";
   display: inline-block;
   position: relative;
   bottom: 2rpx;
   margin-left: 10rpx;
   height: 10px;
   width: 10px;
   border: solid #bbb;
   border-width: 2px 2px 0 0;
 }

 .icon-right::after {
   -webkit-transform: rotate(45deg);
   transform: rotate(45deg);
 }

 .icon-down::after {
   bottom: 14rpx;
   -webkit-transform: rotate(135deg);
   transform: rotate(135deg);
 }

 .icon-up::after {
   bottom: 0rpx;
   -webkit-transform: rotate(-45deg);
   transform: rotate(-45deg);
 }

》》使用方式(引用组件的页面)：

1.pindex.js:

 Page({

   /**
    * 页面的初始数据
    */
   data: {
     selectArray: [{
       "id": "10",
       "value": "会计类"
     }, {
       "id": "21",
       "text": "工程类"
     }, '技术类', {'value': '其他'}]
   },

   select: function(e) {
     console.log(e.detail)
   }

 })

2.pindex.json:

 {
   "navigationBarTitleText":"下拉测试",
   "usingComponents": {
     "single-dropdown-select": "/components/single-dropdown-select/index"
   }
 }

3.pindex.wxml:

 <view class="weui-cell">
     <view class="weui-cell__hd">类型：</view>
     <view class="weui-cell__bd">
       <single-dropdown-select prop-array='{{selectArray}}'  bind:select='select' />
     </view>
   </view>

4.效果图：