CBPeripheralManager防止外围设备断开连接

Question

I'm using both CBCentralManager and CBPeripheralManager in my app. The work I do with PeripheralManager is straightforward - it just add one service with one readable/notify characteristic. That's it.

I connect to discovered CBPeripheral by CentralManager and then cancel the connection: centralManager.cancelPeripheralConnection(peripheral) . I correctly get a delegate callback that peripheral was sucessfully disconnected. I then dealloc all strong references to that CBPeripheral .

What is troubling me is that system was keeping a connection to the peripheral anyway. I can see connected status in Settings app + my BLE device is indicating that it's still connected.

What I found out using memory-graph tool is that CBPeripheralManager holds strong reference to some CBPeripheral which I believe is my device. When I disabled CBPeripheralManager in my app (didn't add any service to it), I could then cancel connection to the peripheral for real .

Is that a bug or a desired behavior?

Answer 1

You might have figured this out by now, but Apple keeps the connection alive for a short period of time after cancelling the connection.

From their documentation :

Because other apps may still have a connection to the peripheral, canceling a local connection does not guarantee that the underlying physical link is immediately disconnected. From the app's perspective, however, the peripheral is considered disconnected, and the central manager object calls the centralManager:didDisconnectPeripheral:error: method of its delegate object.