説明 ：
コア bluetooth フレームワークを使用して BTLE 周辺機器に接続し、周辺機器の識別子をデータベースに保存しています。
同時に、周辺機器との再接続を処理するために周辺機器を配列に保存しています。
しかし、ユーザーが手動でアプリを終了すると、配列が空になります。
そのため、それらの周辺機器を再度接続することはできません。
これで、データベースに周辺機器の識別子があります。
私はそれについて読んだところ、デリゲートメソッドがあることがわかりました
- (NSArray<CBPeripheral *> *)retrievePeripheralsWithIdentifiers:(NSArray<NSUUID *> *)identifiers NS_AVAILABLE(NA, 7_0)
周辺機器を取得しますが、何も返しません。
周辺機器を再び入手するにはどうすればよいですか?
上記のドキュメントもチェックします。周辺機器に再接続する方法について言及したという点で
Retrieving a List of Known Peripherals
The first time you discover a peripheral, the system generates an identifier (a UUID, represented by an NSUUID object) to identify the peripheral. You can then store this identifier (using, for instance, the resources of the NSUserDefaults class), and later use it to try to reconnect to the peripheral using the retrievePeripheralsWithIdentifiers: method of the CBCentralManager class. The following describes one way to use this method to reconnect to a peripheral you’ve previously connected to.
When your app launches, call the retrievePeripheralsWithIdentifiers: method, passing in an array containing the identifiers of the peripherals you’ve previously discovered and connected to (and whose identifiers you have saved), like this:
knownPeripherals =
[myCentralManager retrievePeripheralsWithIdentifiers:savedIdentifiers];
The central manager tries to match the identifiers you provided to the identifiers of previously discovered peripherals and returns the results as an array of CBPeripheral objects. If no matches are found, the array is empty and you should try one of the other two reconnection options. If the array is not empty, let the user select (in the UI) which peripheral to try to reconnect to.
When the user selects a peripheral, try to connect to it by calling the connectPeripheral:options: method of the CBCentralManager class. If the peripheral device is still available to be connected to, the central manager calls the centralManager:didConnectPeripheral: method of its delegate object and the peripheral device is successfully reconnected.
Note: A peripheral device may not be available to be connected to for a few reasons. For instance, the device may not be in the vicinity of the central. In addition, some Bluetooth low energy devices use a random device address that changes periodically. Therefore, even if the device is nearby, the address of the device may have changed since the last time it was discovered by the system, in which case the CBPeripheral object you are trying to connect to doesn’t correspond to the actual peripheral device. If you cannot reconnect to the peripheral because its address has changed, you must rediscover it using the scanForPeripheralsWithServices:options: method.