微信H5页面中软键盘收回时页面不回弹

问题：在微信H5中 ios12 软键盘收回时页面不回弹，导致光标位置错乱，再次点击输入框区域时无法focus

解决思路：失去焦点时滚动下页面

    let ua = window.navigator.userAgent;
    if (!!ua.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/)) {
        //$alert('ios端');
        oInput.onblur = function () {
            var currentPosition, timer;
            var speed = 1;
            timer = setInterval(function () {
                currentPosition = document.documentElement.scrollTop || document.body.scrollTop;
                currentPosition -= speed;
                window.scrollTo(0, currentPosition); //页面向上滚动
                currentPosition += speed;
                window.scrollTo(0, currentPosition); //页面向下滚动
                clearInterval(timer);
            }, 100);
        }
    } else if (ua.indexOf('Android') > -1 || ua.indexOf('Adr') > -1) {
        // console.log('安卓正常')
    }