When you develop an application to communicate with Bluetooth-enabled devices (Classic, LE, Audio), you may need to check if a device is already connected by another application or by the system, and disconnect it so your application can use the device.

The common way to do this is to ask your application's user to use the standard Windows Devices dialog. A user needs to go to Settings, open the Devices tab, find the required device (not an easy task if the device has a "strange" name), and then click the Disconnect button if the device is connected. You need to do this because Windows does not provide any API to disconnect connected Bluetooth-enabled devices. That does not look too user-friendly. Of course, if the device is paired, you can disconnect it programmatically by unpairing. However, that works only for paired devices, removes the device from the system, and requires you to re-pair the device when you need to connect again. This is not the best solution.

However, if your application uses the Bluetooth Framework, you can do all of this programmatically. You can test this feature using the BluetoothManager sample application from the Bluetooth Framework package. Should you have any questions, please do not hesitate to contact us.

Enumerating Connected Bluetooth Devices

In the BluetoothManager sample application, click the Enum connected button to enumerate all currently connected devices. After that, you will see the connected devices list. Please note that even though you can find connected devices when you click Enum paired, not all connected devices are paired. Also, if any UWP application that uses a GATT-enabled device is running, the device used by the application may not be shown because of UWP GATT API limitations. The Bluetooth Framework does not have such limitations, and any BLE device (unless specifically restricted) will be properly connected.

To enumerate the connected Bluetooth-enabled devices in your application, you use the EnumConnectedDevices method of the wclBluetoothRadio class. The method returns a list of the currently connected Bluetooth-enabled devices.

Disconnect a Bluetooth Device

When you have the connected devices list, you are ready to disconnect the required one. Simply select the required device in the devices list and click the Disconnect button. The selected device will be disconnected, and if it was paired, it will remain paired.

To do the same in your application, use the RemoteDisconnect method of the wclBluetoothRadio class. Pass the required device's MAC address to the method, and the device will be disconnected. The Bluetooth Framework can disconnect any Bluetooth-enabled device type: Classic, LE, and Audio. However, using this method to disconnect a Bluetooth audio device may cause some issues. For more details about working with Bluetooth audio devices, refer to this article that describes how to use the Bluetooth Framework to control Bluetooth audio devices.

For more details, please refer to the BluetoothManager sample application source code.