vue axios 在页面切换时中断请求方法

Vue.prototype.$ajax=axios; 
const CancelToken = axios.CancelToken;
let cancel;
let cancelAjaxText = '中断成功';
Vue.prototype.post = function(url,data,loading){
 	var ajax = Vue.prototype.$ajax({
	   	method: 'post',
	   	url:url,
	   	data: data,
	   	cancelToken: new CancelToken(c => { //强行中断请求要用到的
	   	cancel = c
	   	})
	  }).then(res =>res.data,res=>{ //中断请求和请求出错都会走这里，我这里用 cancelAjaxText 来区别
	  	if(res.message == cancelAjaxText){ 
	  		return {status : false,msg:cancelAjaxText}
	  	}else{
	  		this.$confirm('登录过时，是否重新登录', '提示', {
			   	confirmButtonText: '确定',
			   	cancelButtonText: '取消',
			   	type: 'warning'
			  }).then(() => {
			   	window.location.href = Vue.prototype.url_head + '/';
			  }).catch(() => {
			});
	  	}
	})
 return ajax;
};

Vue.prototype.cancelAjax = function(){ //切换页面强行中断请求 router.beforeEach中用到 
 if(cancel){ 
  cancel(cancelAjaxText); 
 } 
}

router.beforeEach((to, from, next) => { 
<span style="white-space:pre;"> </span>Vue.prototype.cancelAjax()  
 next(); 
});

<span style="white-space:pre;">   </span>this.post(this.ajaxUrl + 'getCrTree',{ 
    devAddr : this.changeData.devAddr, 
    innerId : this.changeData.innerId, 
   }).then(ret=>{ 
    if(ret.status){ 
      
    }else{ 
     this.msg(ret.msg); 
    } 
   })