vue.js项目beforeEnter未定义

Question

beforeEnter(el) {    let count = this.balls.length;    while (count--) {        let ball = this.balls[count];        if (ball.show) {            let rect = ball.el.getBoundingClientRect();            let x = rect.left - 32;            let y = -(window.innerHeight - rect.top - 22);            el.style.display = '';            el.style.webkitTransform = `translate3d(0,${y}px,0)`;            el.style.transform = `translate3d(0,${y}px,0)`;            let inner = el.getElementsByClassName('inner-hook')[0];            inner.style.webkitTransform = `translate3d(${x}px,0,0)`;            inner.style.transform = `translate3d(${x}px,0,0)`;        }    }上面代码Uncaught (in promise) TypeError: Cannot read property 'style' of undefined    at VueComponent.beforeEnter (eval at <anonymous> (app.js:744), <anonymous>:99:30)    at Transition.p$1.callHook (eval at <anonymous> (app.js:594), <anonymous>:6843:22)    at Transition.p$1.enter (eval at <anonymous> (app.js:594), <anonymous>:6674:8)    at applyTransition (eval at <anonymous> (app.js:594), <anonymous>:1221:21)    at Directive.apply (eval at <anonymous> (app.js:594), <anonymous>:4804:7)    at Directive.update (eval at <anonymous> (app.js:594), <anonymous>:4796:10)    at VueComponent._update (eval at <anonymous> (app.js:594), <anonymous>:8501:15)    at Watcher.run (eval at <anonymous> (app.js:594), <anonymous>:3455:17)    at runBatcherQueue (eval at <anonymous> (app.js:594), <anonymous>:3186:13)    at Array.flushBatcherQueue (eval at <anonymous> (app.js:594), <anonymous>:3156:5)报错信息

Answer 1

不能直接访问元素的style属性吧