我声明一个onMessage函数做一些事情。但是当我导航到另一个屏幕并想要在ComponentWillUnmount()中删除FCM.onMessage()时。我怎么能删除它?
const rnfirebase = RNFirebase.initializeApp()
export const FCM = rnfirebase.messaging()
ComponentDidMount(){
FCM.onMessage((notif)=>{
//Do something
})
}
ComponentWillUnmount(){
//I want to remove here
}
如果你检查docs onMessage返回一个函数,如果控制台记录该函数,你会看到这样的东西
ƒ () {
return rnListener.remove();
}
因此,当您调用onMessage返回的函数时,它将停止侦听,在您的情况下,代码将如下所示
const rnfirebase = RNFirebase.initializeApp()
export const FCM = rnfirebase.messaging()
componentDidMount(){
this.notificationListener = FCM.onMessage(notif=>{
//Do something
})
}
componentWillUnmount(){
this.notificationListener(); //This will remove the listener
}