Question

我正在尝试制作一款有关蓝牙问题的Android应用。我只是启用蓝牙，查找设备，连接其中一个设备，发送＆amp;接收数据。第一件事就完成了。但第二，存在一些问题。我发了Broadcast Receiver来发现手机附近的设备。但OnReceive方法不会被调用。奇怪的是，它首先被调用，我能够看到附近的设备。然后，我无法弄清楚的事情发生了，现在OnReceive方法没有被调用。我搜索了关于这些的主题，但没有一个可以解决我的问题。 MyDevice和MyAdapter是我自己的类，可以使用我自己的布局在列表视图中显示蓝牙设备。这是我的代码：

public class FoundDevicesActivity extends AppCompatActivity {
BluetoothAdapter bluetoothAdapter;
ListView foundedDevicesListView;
MyDeviceAdapter deviceAdapter;
List<MyDevice> foundedDevicesList;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_found_devices);

    bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    foundedDevicesListView = (ListView) findViewById(R.id.foundDevicesListview);

    if (bluetoothAdapter.isDiscovering()) {
        bluetoothAdapter.cancelDiscovery();
    }

    IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);

    filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
    filter.addAction(BluetoothDevice.ACTION_FOUND);
    filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);

    this.registerReceiver(receiver, filter);
    bluetoothAdapter.startDiscovery();

    deviceAdapter = new MyDeviceAdapter(this, foundedDevicesList);
    foundedDevicesListView.setAdapter(deviceAdapter);
}

private final BroadcastReceiver receiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
            Toast.makeText(FoundDevicesActivity.this, "Discovery is started !!", Toast.LENGTH_SHORT).show();
            Log.d("Found Devices Activity", "Discovery is started !!");
        } else if (BluetoothDevice.ACTION_FOUND.equals(action)) {
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            MyDevice dvc = new MyDevice();
            if (device.getName().equals(null)) {
                dvc.name = "UNDEFINED NAME";
            } else {
                dvc.name = device.getName();
            }

            if(device.getAddress().equals(null)) {
                dvc.address = "UNDEFINED ADDRESS";
            } else {
                dvc.address = device.getAddress();
            }
            foundedDevicesList.add(dvc);
        } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
            bluetoothAdapter.cancelDiscovery();
            Toast.makeText(FoundDevicesActivity.this, "Discovery is finished !!", Toast.LENGTH_SHORT).show();
            Log.d("Found Devices Activity", "Discovery is finished !!");
        }
    }
};

}

有什么想法吗？

蓝牙OnReceive方法不会被调用

0 个答案: