在FastClick的github找到的解决办法，
FastClick.prototype.focus = function (targetElement) { //解决FastClick在ios输入框聚焦慢
let length;
if (targetElement.setSelectionRange && targetElement.type.indexOf('date') !== 0 && targetElement.type !== 'time' && targetElement.type !== 'month') {
length = targetElement.value.length;
targetElement.focus();
targetElement.setSelectionRange(length, length);
} else {
targetElement.focus();
}
}
FastClick.attach(document.body)
