JS 判断用户在触摸屏上的滑动方向 #205
Description
实现过程
Google：js touch up down。
参考方案：Detect a finger swipe through JavaScript on the iPhone and Android。
代码：
let touchstartX = 0
let touchendX = 0
const slider = document.getElementById('slider')
function handleGesture() {
if (touchendX < touchstartX) alert('swiped left!')
if (touchendX > touchstartX) alert('swiped right!')
}
slider.addEventListener('touchstart', e => {
touchstartX = e.changedTouches[0].screenX
})
slider.addEventListener('touchend', e => {
touchendX = e.changedTouches[0].screenX
handleGesture()
})