<view class="marquee_container" style="--marqueeWidth--:-12em">
    <view class="marquee_text">测试跑马灯效果</view>
</view>

@keyframes around {
  from {
   margin-left: 100%;
  }
  to {
   /* var接受传入的变量 */
   margin-left: var(--marqueeWidth--);
  }
 }
 
.marquee_container{
  background-color: #000;
  height: 40rpx;
  line-height: 40rpx;
  position: relative;
  width: 100%;
}
.marquee_container:hover{
  /* 不起作用 */
  animation-play-state: paused;
}
.marquee_text{
  color:#b4b4b4;
  font-size: 28rpx;
  display: inline-block;
  white-space: nowrap;
  animation-name: around;
  animation-duration: 10s;  /*过渡时间*/
  animation-iteration-count: infinite;
  animation-timing-function:linear;
}

//index.js
//获取应用实例
var app = getApp()
Page({
  data: {
    content_t:'测测测测测测测测测测测测测测测测测测测测测测测测测测测测测测测测测测测测测测sss',//内容
    size:12,//宽度即文字大小
    marqueeW:0,
    moveTimes:8,//一屏内容滚动时间为8s
    allT:"0s"
  },
  onLoad: function () {
    var screenW=wx.getSystemInfoSync().windowWidth;//获取屏幕宽度
    var contentW=this.data.content_t.length*this.data.size;//获取文本宽度（大概宽度）
    var allT=(contentW/screenW)*this.data.moveTimes;//文字很长时计算有几屏
    allT=allT<8?8:allT;//不够一平-----最小滚动一平时间
   this.setData({marqueeW:-contentW+"px",allT:allT+"s"});
  }
})

<view class="marquee_container" style="--marqueeWidth--:{{marqueeW}};--allTs--:{{allT}};">
    <view class="marquee_text" style="font-size:{{size}}px">{{content_t}}</view>
</view>

@keyframes around {
  from {
   margin-left: 100%;
  }
  to {
   /* var接受传入的变量 */
   margin-left: var(--marqueeWidth--);
  }
 }
 
.marquee_container{
  background-color: #000;
  height: 40rpx;
  line-height: 40rpx;
  position: relative;
  width: 100%;
}

.marquee_text{
  color:#b4b4b4;
  font-size: 28rpx;
  display: inline-block;
  white-space: nowrap;
  animation: around var(--allTs--)  infinite linear;
}