小程序中下拉框组件

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>

json

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

js

//index.js
Component({
  /**
   * 组件的属性列表
   */
  properties: {
    propArray: {
      type: Array,
    },
    propValue: {
      type: String,
    }
  },
  /**
   * 组件的初始数据
   */
  data: {
    selectShow: false,//初始option不显示
    selectText: "请选择",//初始内容
  },
  lifetimes:{
    attached: function () {
      console.log(this.properties.propValue, 'this.properties.propValue')
      if (this.properties.propValue != '') {
        var nowData = this.properties.propArray;
        var nowIdx = Number(this.properties.propValue-1);//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,
        })
      }
    },
  },

  /**
   * 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])
    }
  }
})

wxss

 /* components/single-dropdown-select/index.wxss */
 
 .ms-content-box {
   300rpx;
  border-radius: 20rpx;
}

.ms-content {
  border: 1rpx solid #0e0a0a;
  background: white;
  font-size: 28rpx;
  position: relative;
  height: 70rpx;
  line-height: 70rpx;
}

.ms-text {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  padding: 0 80rpx 0 20rpx;
  font-size: 28rpx;
}

.ms-options {
  background: white;
   inherit;
  position: absolute;
  border: 1rpx solid #e2e2e2;
  border-top: none;
  box-sizing: border-box;
  z-index: 3;
  max-height: 300rpx;
  overflow: auto;
}

.ms-option {
  height: 70rpx;
  line-height: 70rpx;
  border-top: 1rpx solid #e2e2e2;
  padding: 0 20rpx;
  text-align: left;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 28rpx;
}

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

.icon-right, .icon-down, .icon-up {
  display: inline-block;
  padding-right: 13rpx;
  position: absolute;
  right: 20rpx;
  top: 7rpx;
}

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

app.json

组件的使用

    <view class="check_item" wx:if="{{(isScan==1)}}">
                        <view><text class="c_r">*</text>商品包装:</view>
                        <single-dropdown-select prop-value="" prop-array='{{selectArray}}' data-index="{{ innerIndex }}"
                            data-value="{{currentTracingCodes.goodsPackageInfo}}" bind:select="changeStatusVal">
                        </single-dropdown-select>
                        <view class="p_a c_r f_18" wx:if="{{currentTracingCodes.goodsPackageInfo == ''}}">请选择</view>
                    </view>

/**
   * 页面的初始数据
   */
  data: {
    isScan:0,//扫码页调整为1
    currentTracingCodes:{},
    innerIndex: 0,
    selectArray: [
      { text: '完整', id: 1},
      { text: '不完整', id: 2},
      { text: '商品破碎', id: 3 },
    ],
  
  },

changeStatusVal(event) {
    let innerIndex = event.currentTarget.dataset.index;
    let val = event.detail.id
    this.setData(
      {
        'currentTracingCodes.goodsPackageInfo': val
      })
  },