vue listening return

Mounted: function () {   // may be placed in the use of activated-Alive Keep 
    IF (the window.history && window.history.pushState) { 
        history.pushState ( null , null , document.URL); 
        window.addEventListener ( 'the popstate ', the this .listenBack, false ); 
    }            
}, 
Methods: { 
    listenback () { 
        IF ( to true ) { // must have, or may not be closed 
           // this can turn off the phone Android system 
            document.addEventListener (' WeixinJSBridgeReady ', function () {
　　　　　　　　　　WeixinJSBridge.call ( 'closeWindow');}, to false );
                  // This ios can turn off the phone system, the order can not be changed 
                 WeixinJSBridge.call ( 'closeWindow' ); 
    } 
}, 
beforeRouteLeave (to, from, Next) { 
    window. the removeEventListener ( 'the popstate', the this .listenBack, to false ); 
}