小程序tab切换代码

<!--index.wxml-->
<view class="container">
  <view class="navtap" >
    <a data-current="{{setting.current.key}}" bindtap="clickcurrent" style="color:{{currentSelect.key == 'current'?mainColor:oldcolor}};">
      <text>本期试用</text>
      <text class="activeline" style="background-color:{{currentSelect.key == 'current'?mainColor:whiteColor}};"></text>
    </a>
    <a data-current="{{setting.trailer.key}}" bindtap="clickcurrent" style="color:{{currentSelect.key == 'trailer'?mainColor:oldcolor}};">
      <text>即将上线</text>
      <text class="activeline" style="background-color:{{currentSelect.key == 'trailer'?mainColor:whiteColor}};"></text>
    </a>
    <a data-current="{{setting.report.key}}" bindtap="clickcurrent" style="color:{{currentSelect.key == 'report'?mainColor:oldcolor}};">
      <text>试用报告</text>
      <text class="activeline" style="background-color:{{currentSelect.key == 'report'?mainColor:whiteColor}};"></text>
    </a>
    <a data-current="{{setting.mytry.key}}" bindtap="clickcurrent" style="color:{{currentSelect.key == 'mytry'?mainColor:oldcolor}};">
      <text>我的试用</text>
      <text class="activeline" style="background-color:{{currentSelect.key == 'mytry'?mainColor:whiteColor}};"></text>
    </a>
  </view>
  <block wx:if="{{currentSelect.key == 'current'}}">
    111
  </block>
  <block wx:if="{{currentSelect.key == 'trailer'}}">
    222
  </block>
  <block wx:if="{{currentSelect.key == 'report'}}">
    333
  </block>
  <block wx:if="{{currentSelect.key == 'mytry'}}">
    444
  </block>
</view>

js

//index.js
//获取应用实例
const app = getApp()

Page({
  data: {
    motto: '首页',
    setting: {
      current: {
        key: "current",
      },
      trailer: {
        key: "trailer"
      },
      report: {
        key: "report"
      },
      mytry: {
        key: "mytry"
      }
    },
    mainColor: '#91d8d2',
    oldcolor: 'grey'
  },
  currentSelect: {},
  onLoad: function () {
     this.setData({
       'currentSelect.key': 'current'
     })
  },
  clickcurrent: function (event) {
    var that = this
    that.setData({
      'currentSelect.key':event.currentTarget.dataset.current
    })  
  } 
})

wxss

/**index.wxss**/

.navtap{
    width:100%;
    height:40px;
    text-align:center;
    display:flex;
    font-size:15px;
    color:#838995;
    background-color:#fff;

}

.navtap a{
    flex:1;
    color:#838995;
    line-height:38px;
}

.activeline{
    width:26px;
    height:2px;
    background-color:#fff;
    display:block;
    margin:0 auto;
}
.navtap a {
    flex:1;
    color:#838995;
    line-height:38px;
}