如何确保应用程序与蓝牙 LE 设备断开连接？

Question

我有两个正在连接的设备。当我离开应用程序时，我会断开与设备的连接。两者都经历相同的过程，但有时其中一个设备会保持连接，直到我强制关闭应用程序。

我的设备上有指示灯，确认它仍然认为它已连接，并且应用程序的其他实例无法连接到它，直到我强行关闭第一个实例。在下面的日志中，第一个列出的设备保持连接。

//call gatt.disconnect();
BluetoothGatt: cancelOpen() - device: F0:3D:A0:04:CA:E7
BluetoothGatt: onClientConnectionState() - status=0 clientIf=7 device=F0:3D:A0:04:CA:E7

//wait for connection state change callback then call gatt.close();
BluetoothGatt: close()
BluetoothGatt: unregisterApp() - mClientIf=7

//call gatt.disconnect();
BluetoothGatt: cancelOpen() - device: FF:A9:CA:EF:08:A4
BluetoothGatt: onClientConnectionState() - status=0 clientIf=5 device=FF:A9:CA:EF:08:A4

//wait for connection state change callback then call gatt.close();
BluetoothGatt: close()
BluetoothGatt: unregisterApp() - mClientIf=5

调用 gatt.close() 后，我获取蓝牙管理器并在已连接设备列表中查找我的设备。它在列表中。

从BluetoothGattCallback

public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
    super.onConnectionStateChange(gatt, status, newState);
    final String address = gatt.getDevice().getAddress();
    if (newState == BluetoothProfile.STATE_CONNECTED) {
        onConnected(gatt, address);
    } else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
        onDisconnected(gatt, address);
    }
}

private void onDisconnected(BluetoothGatt gatt, String address) {
    Log.v(TAG, address + " disconnected");
    if (devices.containsKey(address)) {
        devices.get(address).setState(Connection.STATE_DISCONNECTED);
        connect(gatt.getDevice());
    } else {
        gatt.close();
        verifyDisconnect(gatt, address);
    }
}

private void verifyDisconnect(BluetoothGatt gatt, String address) {
    BluetoothManager bluetoothManager = (BluetoothManager) context.getSystemService(Context.BLUETOOTH_SERVICE);
    final List<BluetoothDevice> devices = bluetoothManager.getConnectedDevices(BluetoothProfile.GATT);
    for (final BluetoothDevice device : devices) {
        if (device.getAddress().equals(address)) {
            Log.d(TAG, address + " is still connected!!!!");
            addCommand(new DisconnectCommand(gatt));
            break;
        }
    }
}

此类被添加到命令队列中。

public class DisconnectCommand extends BluetoothCommand {

    private final BluetoothGatt gatt;

    public DisconnectCommand(BluetoothGatt gatt) {
        this.gatt = gatt;
        priority = BluetoothCommand.DISCONNECT_PRIORITY;
    }

    public boolean execute() {
        gatt.disconnect();
        return true;
    }
}

Answer 1

尝试：

public void disconnect() {
    if (blegatt== null) {
        Log.w(TAG, "BluetoothAdapter not initialized");
    }
    else {
        bleGatt.disconnect();
        close();
        gatt = null;
    }
}
/**
 * After using a given BLE device, the app must call this method to ensure resources are
 * released properly.
 */
public void close() {
    if (gatt == null) {
        return;
    }
    gatt.close();
}