微信小程序文字滾動marquee

 data: {
      text: "如果預約時間不能到店則需要提前兩個小時取消預約，如不足兩個小時可聯系技師取消預約",
        marqueePace: 0.5,//滾動速度
        marqueeDistance: 0,//初始滾動距離
        marquee_margin: 0,
        size:28,
        interval: 20 // 時間間隔
  },

onShow: function () {
        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();// 第一個字消失后立即從右邊出現
 },
  
 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
        if (length > windowWidth){
               var interval = 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值等於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 {
                     //console.log("替換");
                     that.setData({
                      marqueeDistance: 0 // 直接重新滾動
                     });
                     clearInterval(interval);
                     that.scrolltxt();
                }
               }, that.data.interval);
        }else{
              that.setData({ marquee_margin:"1000"});//只顯示一條不滾動右邊間距加大，防止重復顯示
        } 
 },

<view class="pad_25">
    <view class=" dis_f ali_ct">
        <view><image src="/images/laba_wode.png" class="dis_b laba_img_w" /></view>
        <view class="clr_g flex1" >
            <scroll-view  >
                 <view class="scrolltxt clr_g">
                  <view class="marquee_box">
                   <view class="marquee_text" style="transform: translateX(-{{marqueeDistance}}px)">
                    <text class="clr_g">{{text}}</text>
                    <text style="margin-right:{{marquee_margin}}px;"  class="clr_g"></text>
                    <text style="margin-right:{{marquee_margin}}px;" class="clr_g">{{text}}</text>    
                   </view>
                  </view>
                 </view>
            </scroll-view>
        </view>

    </view>
</view>

.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:28rpx;height:90rpx;line-height:90rpx;}

效果