微信小程序实现文字跑马灯的方法

 {{announ}}

export default class ShopIndex extends wepy.page {

 config = {
 navigationBarTitleText : '首页',
 }

 data = {
 // 公告内容
 announ : '超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度超长度v',
 announNum : 0,
 announy : 280,
 announZf : '-'
 }

 onLoad() {
 
 let self = this;
 var query = wepy.createSelectorQuery();
 query.select('.content').boundingClientRect(ContentRes => {
  var query = wepy.createSelectorQuery();
  query.select('.every').boundingClientRect(TextRes => {

  //加上一百是因为防止在归零时出现闪烁的情况
  let maxContentWidth = ContentRes.width + 100,
  maxTextWidth = TextRes.width;
  //初始化
  self.announNum = TextRes.width
  self.$apply();

  //定时器
  setInterval(()=>{
   if(self.announZf == '-') {
   if(self.announNum <= 0) {
    self.announZf = ''
   } else {
    self.announNum -= 1
   }
   } else {
   if(self.announNum > (maxContentWidth)) {
    //归位
    self.announZf = '-'
    self.announNum = maxTextWidth
   } else {
    self.announNum += 1
   }
   } 
   self.$apply();  
  },5)
  }).exec();
 }).exec();

 }
 }