<ul class="list">
 <li class="item" v-for="item of letters"
 :key="item"
 :ref="item"
 @touchstart="handleTouchStart"
 @click="handleleterClick"
 >{{item}}</li>
 </ul>

 <ul class="list">
 <li class="item" v-for="item of letters"
 :key="item"
 :ref="item"
 @touchstart.stop.prevent="handleTouchStart"
 @click="handleleterClick"
 >{{item}}</li>
 </ul>

 methods: {
 handleleterClick (e) {
  console.log('click事件执行一次')
  this.$emit('change', e.target.innerText)
 },
 handleTouchStart (e) {
  console.log('TouchStart执行一次')
  e.preventDefault()//添加阻止click事件触发
  this.touchStatus = true
 }
 }
}

 <ul class="list">
 <li class="item" v-for="item of letters"
 :key="item"
 :ref="item"
 @click="handleSelfClick"
 >{{item}}</li>
 </ul>

 methods: {
 handleleterClick (e) {
  console.log('click事件执行一次')
  this.$emit('change', e.target.innerText)
 },
 handleTouchStart (e) {
  console.log('TouchStart执行一次')
  this.touchStatus = true
 },
 handleSelfClick (e) {
  console.log('ontouchstart' in document)//打印是否支持touch事件。
  if ('ontouchstart' in document) {
  this.handleTouchStart(e)
  } else {
  this.handleleterClick(e)
  }
 }
 }