微信小程序如何實(shí)現(xiàn)簡單文字跑馬燈

<scroll-view class="container">
 <view class="scrolltxt">
 <view class="marquee_box">
 <view class="marquee_text" >
 <text>{{text}}</text>
 <text ></text>
 <text >{{text}}</text> 
 </view>
 </view>
 </view>
</scroll-view>

.container {display: flex;flex-direction: column;justify-content: space-between;box-sizing: border-box;}
.scrolltxt{padding:0 20rpx;background:#f8f8f8;}
.marquee_box {position:relative;color:#333;height:90rpx;display:block;overflow:hidden;} 
.marquee_text {white-space: nowrap;position:absolute;top:0;font-size:14px;height:90rpx;line-height:90rpx;}

 data: {
 //滾動字幕
 text: "溫馨提示：為了保證其他購買者的利益，每個(gè) 賬號針對同一商品只允許退款一次，請您謹(jǐn)慎操作。",
 marqueePace: 1,//滾動速度
 marqueeDistance: 0,//初始滾動距離
 marquee_margin: 30,//間距
 size: 14,//字號
 time: '',// 定時(shí)器
 },

onHide: function () {
 //清空滾動字幕定時(shí)器，避免鎖屏或頁面隱藏后移動速度越來越快
 clearInterval(this.data.time);
 },

 onShow: function (e) {
 var that = this;
 var length = that.data.text.length * that.data.size;//文字長度
 var windowWidth = wx.getSystemInfoSync().windowWidth;// 屏幕寬度
 //console.log(length,windowWidth);
 that.setData({
 length: length,
 windowWidth: windowWidth
 });
 that.scrolltxt();// 第一個(gè)字消失后立即從右邊出現(xiàn)
 },

 /**
 * 滾動字幕
 */
 scrolltxt: function () {
 var that = this;
 var length = that.data.length;//滾動文字的寬度
 var windowWidth = that.data.windowWidth;//屏幕寬度
 var time = this.data.time
 if (length > windowWidth) {
 time = setInterval(function () {
 var maxscrollwidth = length + that.data.marquee_margin;//滾動的最大寬度，文字寬度+間距，如果需要一行文字滾完后再顯示第二行可以修改marquee_margin值等于windowWidth即可
 var crentleft = that.data.marqueeDistance;
 if (crentleft < maxscrollwidth) {//判斷是否滾動到最大寬度
  that.setData({
  marqueeDistance: crentleft + that.data.marqueePace
  })
 }
 else {
  that.setData({
  marqueeDistance: 0 // 直接重新滾動
  });
  clearInterval(time);
  that.scrolltxt();
 }
 }, 20);
 }
 else {
 that.setData({ marquee_margin: "1000" });//只顯示一條不滾動右邊間距加大，防止重復(fù)顯示
 }
 that.setData({
 time:time
 })
 },