vue—依赖注入

export default {
        name: ‘app‘,
        data(){
            return {
                msg:‘Welcome to Your Vue.js App‘
            }
        },
        provide(){
            return {
                msg:this.msg
            }
        },
}

export default{
        data(){
            return {
                children:‘this is children component.‘
            }
        }
        inject:[‘msg‘],
}
//使用方式
<span>{{msg}}</span>     //    this.msg