代码如下：

changeTask: function(e) {       var direction = e.detail.direction //滑动方向     console.log(JSON.stringify(e))     if (direction == 1) { //左滑       if (this.currentSwiper > 0 && this.currentSwiper <= this.tasks.length - 1) {         cSwiper -= 1       }     } else if (direction == 2) { //右滑       if (this.currentSwiper >= 0 && this.currentSwiper < this.tasks.length - 1)         cSwiper += 1     } else { //没有滑动       cSwiper = cSwiper     }     this.setData({       currentSwiper: cSwiper     })     console.log("direction:" + direction + ";;this.currentSwiper:" + this.currentSwiper + ";;currentSwiper::" + cSwiper)     }   })

其中cSwiper在 Page 上面定义的，即：

var cSwiper = 0

Page({

…

})

log输出为：

direction:2;;this.currentSwiper:undefined;;currentSwiper::0

即：data中的变量currentSwiper为undefined