问题
My issue (background notifications):
I am using React Native Firebase. Everything is fine until recently I updated to version 6.7.1 of the library. After the update background notification(while app is closed) stopped working. Foreground is working.
I found a suggestion here, to turn FirebaseAppDelegateProxyEnabled to YES in info.plist.
And it did work! I can receive notifications fine now.
But what is swizzling?
I don't really understand what is this method of swizzling do, and what is the difference between setting it YES or NO do?
I read about it in firebase documentation: Method swizzling in Firebase Cloud Messaging. I couldn't get it really.
Can someone explain in a clearer way, and what difference does it make?
来源：https://stackoverflow.com/questions/61753520/what-does-firebaseappdelegateproxyenabled-do