<view class="navbar"> 
 <text wx:for="{{navbar}}" data-index="{{index}}" 
 class="item {{currentIndex==index?'active':''}}" 
 bindtap="navbarTab" wx:key="unique">{{item}}</text> 
 </view> 
 <view hidden="{{currentIndex!==0}}"> 
 
 </view> 
 <view hidden="{{currentIndex!==1}}"> 
 
 </view>

.navbar{ 
 display: flex; 
 width: 100%; 
 flex-direction: row; 
 line-height: 80rpx; 
 position: fixed; 
 top: 0; 
} 
.navbar .item{ 
 flex: auto; 
 font-size: 30rpx; 
 text-align: center; 
 background: #fff; 
 font-weight: bold; 
} 
.navbar .item.active{ 
 color: #36DB2C; 
 position: relative; 
} 
.navbar .item.active::after{ 
 content: ""; 
 display: block; 
 position: absolute; 
 height: 4rpx; 
 bottom: 0; 
 left: 0; 
 right: 0; 
 background: #36DB2C; 
} 

data: { 
 navbar: ["我发出的", "我收到的"], 
 currentIndex: 0,//tabbar索引 
 }, 
 navbarTab: function (e) { 
 this.setData({ 
  currentIndex: e.currentTarget.dataset.index 
 }); 
 },