navBar.wxml

<!-- 底部导航条 -->
<view class="navBar">
  <view class="navBar-home" bindtap=‘goHome‘>
    <image wx:if="{{homeActive}}" src="../../public/index_tabBar1.png"></image>
    <image wx:if="{{!homeActive}}" src="../../public/index_tabBar1_nor.png"></image>
    <text>首页</text>
  </view>
  <view class="navBar-explore" bindtap=‘goExplore‘>
    <image wx:if="{{exploreActive}}" src="../../public/index_tabBar2.png"></image>
    <image wx:if="{{!exploreActive}}" src="../../public/index_tabBar2_nor.png"></image>
    <text>发现</text>
  </view>
  <view class="navBar-user" bindtap=‘goUser‘>
    <image wx:if="{{userActive}}" src="../../public/index_tabBar3.png"></image>
    <image wx:if="{{!userActive}}" src="../../public/index_tabBar3_nor.png"></image>
    <text>我的</text>
  </view>
</view>

navBar.wxss

/* 底部导航条 */
.navBar {
  width: 100%;
  padding: 18rpx 0;
  border-top: 1rpx solid #cccccc;
  display: flex;
  justify-content: space-around;
  position: fixed;
  bottom: 0;
  background: #fff;
}
.navBar image {
  width: 55rpx;
  height: 55rpx;
}
.navBar view {
  display: flex;
  flex-direction: column;
  align-items: center;
  font-size: 20rpx;
  color: #999999;
}
.navBar-user text {
  color: #d0a763;
}

navBar.js

// pages/componentNavBar/navBar.js
Component({
  /**
   * 组件的属性列表
   */
  properties: {
    homeActive: {
      type: Boolean,
      value: false
    },
    exploreActive: {
      type: Boolean,
      value: false
    },
    userActive: {
      type: Boolean,
      value: false
    }
  },

  /**
   * 组件的初始数据
   */
  data: {

  },

  /**
   * 组件的方法列表
   */
  methods: {
    // 返回首页
    goHome: function (e) {
      wx.switchTab({
        url: ‘../index/index‘,
      })
    },
    // 返回发现页 
    goExplore: function (e) {
      wx.switchTab({
        url: ‘../explore/explore‘,
      })
    },
    // 返回我的页面
    goUser: function (e) {
      wx.switchTab({
        url: ‘../user/user‘,
      })
    },
    showCode: function(e) {
      console.log(e);
      let that = this;
      console.log(that.data);
    }
  }
})

navBar.json

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

父组件 .wxml

<view>
  <navBar userActive="{{userActive}}"></navBar>
</view>

父组件 .json

{
  "usingComponents": {
    "navBar": "../componentNavBar/navBar"
  }
}

父组件 .js

data: {
  userActive: true
},

微信小程序 tab组件