$emit传递一个参数的情况

//child组件，在子组件中触发事件
this.$emit('handleFather', param)
//father组件，在父组件中引用子组件
<child @handleFather="handleFather"></child>
//或者
//<child @handleFather="handleFather($event)"></child>

<script>
    export default {
      components: {
       child,
      }
      methods: {
        handleFather(param) {
            console.log(param)
        }
      }
    },
</script>

$emit传递多个参数的情况

//child组件，在子组件中触发事件并传多个参数
this.$emit('handleFather', param1, param2,)
//father组件，在父组件中引用子组件
<child @handleFather="handleFather(arguments)"></child>

<script>
    export default {
      components: {
       child,
      }
      methods: {
        handleFather(param) {
            console.log(param[0]) //获取param1的值
            console.log(param[1]) //获取param2的值

        }
      }
    },
</script>

当需要父组件本身传参时

//child组件，在子组件中触发事件
this.$emit('handleFather', param)
//father组件，在父组件中引用子组件
<child @handleFather="handleFather($event, fatherParam)"></child>

<script>
    export default {
      components: {
       child,
      }
      methods: {
        handleFather(childParam, fatherParam) {
            console.log(childParam)
            console.log(fatherParam)
        }
      }
    },
</script>

//child组件，在子组件中触发事件并传多个参数
this.$emit('handleFather', param1, param2,)
//father组件，在父组件中引用子组件
<child @handleFather="handleFather(arguments, fatherParam)"></child>

<script>
    export default {
      components: {
       child,
      }
      methods: {
        handleFather(childParam, fatherParam) {
            console.log(childParam) //获取arguments数组参数
            console.log(fatherParam) //获取fatherParam

        }
      }
    },
</script>