前端Input在IOS不聚焦，难选中

在main.js添加如下代码

FastClick.attach(document.body)
FastClick.prototype.focus = function(targetElement) {
  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()
  }
}