export default {
 mounted: function () {
 this.$nextTick(function () {
 this.$on('childMethod', function () {
 console.log('監聽成功')
 })
 })
 }，
 methods {
 callMethod () {
 console.log('調用成功')
 }
 }
}

<child ref="child" @click="click"></child>

export default {
 methods: {
 click () {
 this.$refs.child.$emit('childMethod') // 方法1
 this.$refs.child.callMethod() // 方法2
 },
 components: {
 child: child
 }
}