一開始採用的是這種做法：監聽keydown事件，然後根據鍵值禁用預設事件，發現不可行，原始碼如下

 mounted () {
    window.addEventListener('keydown', this.onClick)
}
  onClick (val) {
      console.log('按下' + val.key)
      console.log('keycode:' + val.keyCode)
      console.log('thiscode:' + this.code)
      if (val.keyCode === 9) {
        console.log('tabfalse13')
        val.keyCode = 0
        val.returnValue = false
        val.which = 0
        val.preventDefault()
        val.stopPropagation()
        val.cancelBubble = true
        window.event.keyCode = 0
        window.event.returnValue = false
        window.event.which = 0
        window.event.preventDefault()
        window.event.stopPropagation()
        window.event.cancelBubble = true
        return false
      }
}
 

原因可能是因為這裡傳入的val並不是原鍵盤事件，所以採取下面的方法發現是可以的

window.addEventListener('keydown', event => {
      console.log('按下' + event.key)
      console.log('keycode:' + event.keyCode)
      console.log('thiscode:' + this.code)
      if (event.keyCode === 9) {
        console.log('tabfalse13')
        event.preventDefault()
      }
}
 

然後記得離開頁面要銷燬監聽

 destroyed () {
   
    window.removeEventListener('keydown', event => {
      console.log(event.value)
      event.preventDefault()
    })

這樣的話按下tab鍵就不會在瀏覽器內切換了，只是有輸出