1.全局守卫:
beforeEach-全局路由前置守卫,afterEach-全局路由后置守卫
2.组件内守卫:Enter | Updata |  Leave
beforeRouterEnter,beforeRouterUpdata,beforeRouterLeave
3.独享守卫:beforeEnter,在路由配置中直接用的守卫函数