CoreBluetooth：应用重装后能否恢复外设及CBCentralManager对象？

Great question—this is a common point of confusion with Core Bluetooth's state restoration, especially when dealing with app reinstalls. Let's break this down clearly:

1. Can a CBCentralManager created with CBCentralManagerOptionRestoreIdentifierKey be restored after app uninstall/reinstall? #

Short answer: No.

iOS stores all state restoration data for your CBCentralManager directly in your app's sandbox container. When you uninstall an app, the entire sandbox is completely wiped—including any saved restoration state tied to your custom restore identifier. Even if you use the exact same CBCentralManagerOptionRestoreIdentifierKey when initializing the manager after reinstalling, there’s no existing state to pull from. The system will treat this as a brand new manager instance with zero prior connection history.

2. How to reconnect to known peripherals after reinstall? #

Since you’re already storing peripheral IDs on your server (smart move, given they don’t change), here’s a step-by-step approach to re-establish connections:

• Reinitialize your CBCentralManager: You can still use the same restore identifier to enable state restoration for future app launches (like background terminations and relaunches), but keep in mind no past state will be restored this time around. Don’t forget to handle the centralManagerDidUpdateState(_:) delegate callback to confirm Bluetooth is available, and note that you’ll need to request Bluetooth permissions again—iOS doesn’t retain app permissions across uninstalls.
• Retrieve known peripherals: Once your manager is in a ready state, use the retrievePeripherals(withIdentifiers:) method, passing in the UUIDs you fetched from your server. This returns CBPeripheral instances for peripherals iOS has encountered before (pairing info is stored system-wide, not in your app sandbox, so this works even after reinstall).
• Initiate reconnection: For each CBPeripheral you retrieve, call connect(_:options:) to start the connection process. Be sure to implement delegate methods like centralManager(_:didConnect:) and centralManager(_:didFailToConnect:error:) to handle success and failure cases gracefully.
• Handle missing peripherals: If retrievePeripherals(withIdentifiers:) returns an empty array, it means iOS doesn’t have a record of those peripherals (or they’re out of range). In this case, start a scan with scanForPeripherals(withServices:options:) to rediscover them, then connect once they’re found.

Quick Additional Notes #

• Pairing persistence: If your peripherals require pairing, iOS will usually retain bonding data system-wide—so users won’t have to re-pair after reinstalling your app. Your app will still need to create a fresh connection session, though.
• Future state restoration: After reconnecting to peripherals post-reinstall, the system will start saving new state restoration data for future app launches. This won’t help with the initial reinstall scenario, but it will work for subsequent app restarts.

内容的提问来源于stack exchange，提问作者saikamesh