document.body.addEventListener('touchmove', function (e) { e.preventDefault() }, { passive: false })

function stopDown(el) {
    let startX, startY;
    // el是最外層div 
    el.addEventListener("touchstart", (e) => {
        startX = e.changedTouches[0].pageX;
        startY = e.changedTouches[0].pageY;
    })
    el.addEventListener("touchmove", (e) => {
        //獲取滑動(dòng)屏幕時(shí)的X,Y
        let endX = e.changedTouches[0].pageX;
        let endY = e.changedTouches[0].pageY;
        //獲取滑動(dòng)距離
        let distanceX = endX - startX;
        let distanceY = endY - startY;
        //判斷滑動(dòng)方向
        if (Math.abs(distanceX) > Math.abs(distanceY) && distanceX > 0) {
            // console.log('往右滑動(dòng)');
        } else if (Math.abs(distanceX) > Math.abs(distanceY) && distanceX < 0) {
            // console.log('往左滑動(dòng)');
        } else if (Math.abs(distanceX) < Math.abs(distanceY) && distanceY < 0) {
            // console.log('往上滑動(dòng)');
        } else if (Math.abs(distanceX) < Math.abs(distanceY) && distanceY > 0) {
            // 核心在這  
            // path 是從觸摸點(diǎn)到最外層所有祖先節(jié)點(diǎn)的集合,不了解就log看下
            let path = e.path
            let is_scrollTop = false
            // 從觸摸點(diǎn)到最外層所有祖先節(jié)點(diǎn) scrollTop不為0就不禁止下拉 為0 就禁止下拉
            for (let dom of path) {
                if (dom.scrollTop) {
                    is_scrollTop = true
                }
            }
            if (!is_scrollTop) {
                e.preventDefault()
                return false
            }
            // console.log('往下滑動(dòng)');
        } else {
            // console.log('點(diǎn)擊未滑動(dòng)');
        }
    })
}