Android 扫描蓝牙设备

Android扫描蓝牙设备是个异步的过程，核心的步骤为：调用bluetoothAdapter的startDiscovery()进行设备扫描，扫描的结果通过广播接收处理！具体如下：

1.申请相关权限

<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
    <uses-permission android:name="android.permission.BLUETOOTH"/>

2.注册广播

private void registerBroadcast() {
        // Register for broadcasts when a device is discovered
        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        mContext.registerReceiver(mReceiver, filter);

        // Register for broadcasts when discovery has finished
        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        mContext.registerReceiver(mReceiver, filter);
    }

3.扫描设备

private void doDiscovery() {
        // If we're already discovering, stop it
        if (mBluetoothAdapter.isDiscovering()) {
            mBluetoothAdapter.cancelDiscovery();
        }
        // Request discover from BluetoothAdapter
        mBluetoothAdapter.startDiscovery();
    }

4.广播中处理扫描到的设备

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                // TODO discovery finds a device
                
            } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED
                    .equals(action)) {
                // TODO discovery is finished
            }
        }
    };