微信小程序数字滚动小插件

用es6语法方式写了个微信小程序小插件–数字滚动；

效果图：

wxml页面布局代码：

<!--pages/main/index.wxml--><view class="animate-number">     <view class="num num1">{{num1}}{{num1Complete}}</view>     <view class="num num2">{{num2}}{{num2Complete}}</view>     <view class="num num3">{{num3}}{{num3Complete}}</view>     <view class="btn-box">         <button bindtap="animate"  type="primary" class="button">click me</button>     </view></view>

index.js调用NumberAnimate.js

// pages/main/index.jsimport NumberAnimate from "../../utils/NumberAnimate";Page({   data:{        },   onLoad:function(options){     // 页面初始化 options为页面跳转所带来的参数        },   onReady:function(){        },   onShow:function(){          // 页面显示   },   onHide:function(){     // 页面隐藏   },     onUnload:function(){     // 页面关闭     },   //调用NumberAnimate.js中NumberAnimate实例化对象，测试3种效果  animate:function(){      this.setData({      num1:'',      num2:'',      num3:'',      num1Complete:'',      num2Complete:'',      num3Complete:''    });       let num1 = 18362.856;     let n1 = new NumberAnimate({         from:num1,//开始时的数字         speed:2000,// 总时间         refreshTime:100,//  刷新一次的时间         decimals:3,//小数点后的位数         onUpdate:()=>{//更新回调函数           this.setData({             num1:n1.tempValue          });         },         onComplete:()=>{//完成回调函数             this.setData({               num1Complete:" 完成了"             });         }     });       let num2 = 13388;     let n2 = new NumberAnimate({         from:num2,         speed:1500,         decimals:0,         refreshTime:100,         onUpdate:()=>{           this.setData({             num2:n2.tempValue          });         },         onComplete:()=>{             this.setData({               num2Complete:" 完成了"             });         }     });       let num3 = 2123655255888.86;     let n3 = new NumberAnimate({         from:num3,         speed:2000,         refreshTime:100,         decimals:2,         onUpdate:()=>{           this.setData({             num3:n3.tempValue          });         },         onComplete:()=>{             this.setData({               num3Complete:" 完成了"             });         }     });  }})

NumberAnimate.js代码：

/**  * Created by wangyy on 2016/12/26.  */'use strict';class NumberAnimate {       constructor(opt) {         let def = {             from:50,//开始时的数字             speed:2000,// 总时间             refreshTime:100,// 刷新一次的时间             decimals:2,// 小数点后的位数             onUpdate:function(){}, // 更新时回调函数             onComplete:function(){} // 完成时回调函数         }         this.tempValue = 0;//累加变量值         this.opt = Object.assign(def,opt);//assign传入配置参数         this.loopCount = 0;//循环次数计数         this.loops = Math.ceil(this.opt.speed/this.opt.refreshTime);//数字累加次数         this.increment = (this.opt.from/this.loops);//每次累加的值         this.interval = null;//计时器对象         this.init();     }     init(){         this.interval = setInterval(()=>{this.updateTimer()},this.opt.refreshTime);     }       updateTimer(){                  this.loopCount++;         this.tempValue = this.formatFloat(this.tempValue,this.increment).toFixed(this.opt.decimals);         if(this.loopCount >= this.loops){             clearInterval(this.interval);             this.tempValue = this.opt.from;             this.opt.onComplete();         }         this.opt.onUpdate();     }     //解决0.1+0.2不等于0.3的小数累加精度问题     formatFloat(num1, num2) {         let baseNum, baseNum1, baseNum2;         try {             baseNum1 = num1.toString().split(".")[1].length;         } catch (e) {             baseNum1 = 0;         }         try {             baseNum2 = num2.toString().split(".")[1].length;         } catch (e) {             baseNum2 = 0;         }         baseNum = Math.pow(10, Math.max(baseNum1, baseNum2));         return (num1 * baseNum + num2 * baseNum) / baseNum;     };}export default  NumberAnimate;