未捕获（承诺）ReferenceError：未定义ModifyVideoDoneWindow-ServiceWorker

Question

我正在尝试实施Google推送通知，但是服务工作者遇到问题。一切正常，但突然我开始在控制台中收到此错误消息。 当我从onMessage函数（当页面中的用户使用）调用函数ModifyVideoDoneWindow（payload）时，没有问题。 我认为问题在于范围。

错误：“未捕获（承诺）ReferenceError：未定义ModifyVideoDoneWindow”

// Initialize the Firebase app in the service worker by passing the config.
firebase.initializeApp(config);

self.addEventListener('notificationclick', (event) => {
    event.waitUntil(self.clients.openWindow('http://localhost:8080/#videodone'));
event.notification.close();
});

// Retrieve an instance of Firebase Messaging so that it can handle   background messages.
const messaging = firebase.messaging();

// Handle Messages, when the page is closed.
messaging.setBackgroundMessageHandler( (payload) => {
console.log('Received background message in the service worker PAYLOAD',  payload);
console.log("Notification status: ", payload.data.status);

// Customize notification here
var notificationTitle = 'Video Making Tool';
var notificationOptions = {
    body: 'Your video is ready.',
    icon: '/logo......'
};

modifyVideoDoneWindow(payload);

return self.registration.showNotification(notificationTitle, notificationOptions);

}）;