我尝试并在网络上关注了一些教程，但它在新的Android版本上无效。
我声明了所有蓝牙权限并使用了Dexter权限库。我遵循了几个答案，但它也没有显示可用的蓝牙设备名称
以下是我的代码：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
scan.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
toast("starts scanning...");
mBluetoothAdapter.startDiscovery();
}
});
mAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1);
mListView.setAdapter(mAdapter);
mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String bluetoothDevice = mAdapter.getItem(i);
toast(bluetoothDevice);
}
});
}
public void pairedDevicesListView(View view){
mAdapter.clear();
pairedDevices = mBluetoothAdapter.getBondedDevices();
for (BluetoothDevice device : pairedDevices){
mAdapter.add(device.getName() + "\n" + device.getAddress());
}
}
}
答案 0 :(得分：2)
添加清单权限，如下所示
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />`
并尝试以下代码：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnstart=findViewById(R.id.btnstart);
mListView=findViewById(R.id.listofdevices);
final ArrayAdapter mAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1);
mListView.setAdapter(mAdapter);
txt1=findViewById(R.id.txt1);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
setdevicevisible();
boolean hasBluetooth = getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH);
if(!hasBluetooth) {
AlertDialog dialog = new AlertDialog.Builder(MainActivity.this).create();
dialog.setTitle(getString(R.string.bluetooth_not_available_title));
dialog.setMessage(getString(R.string.bluetooth_not_available_message));
dialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// Closes the dialog and terminates the activity.
dialog.dismiss();
MainActivity.this.finish();
}
});
dialog.setCancelable(false);
dialog.show();
}
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions((Activity) this,
new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
1);
}
// If another discovery is in progress, cancels it before starting the new one.
if (mBluetoothAdapter.isDiscovering()) {
mBluetoothAdapter.cancelDiscovery();
}
mBluetoothAdapter.startDiscovery();
mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
//Finding devices
if (BluetoothDevice.ACTION_FOUND.equals(action))
{
// Get the BluetoothDevice object from the Intent
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// Add the name and address to an array adapter to show in a ListView
mAdapter.add(device.getName() + "\n" + device.getAddress());
}
}
};
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter);
}
答案 1 :(得分：1)
您可以将MAC地址用作唯一ID。
你可以在官方文档中找到它的完整例子
https://developer.android.com/guide/topics/connectivity/bluetooth.html#FindingDevices
关于信号强度我认为您应该使用RSSI（接收信号强度指示器）
编辑：完成此操作的简单方法就像找到蓝牙设备的代码片段
mBluetoothAdapter.startDiscovery();
mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
//Finding devices
if (BluetoothDevice.ACTION_FOUND.equals(action))
{
// Get the BluetoothDevice object from the Intent
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// Add the name and address to an array adapter to show in a ListView
mArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
}
};
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter);
希望有所帮助
快乐编码
答案 2 :(得分：1)
要发现设备，请先致电BluetoothAdapter.getDefaultAdapter()
BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();
要开始发现，只需从蓝牙适配器调用startDiscovery()即可。此过程是异步的，因此它将立即返回。要捕获发现过程，我们可以使用ACTION_FOUND，ACTION_DISCOVERY_STARTED，ACTION_DISCOVERY_STARTED注册BroadcastReceiver。对于找到的每个设备，意图将携带包含BluetoothDevice对象的额外字段EXTRA_DEVICE。
IntentFilter filter = new IntentFilter();
filter.addAction(BluetoothDevice.ACTION_FOUND);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(mReceiver, filter);
adapter.startDiscovery();
接收者：
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
//discovery starts, we can show progress dialog or perform other tasks
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
//discovery finishes, dismis progress dialog
} else if (BluetoothDevice.ACTION_FOUND.equals(action)) {
//bluetooth device found
BluetoothDevice device = (BluetoothDevice) intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
showToast("Found device " + device.getName());
}
}
};
并且，不要忘记在Activity的onDestroy方法上取消注册接收器：
@Override
public void onDestroy() {
unregisterReceiver(mReceiver);
super.onDestroy();
}
答案 3 :(得分：1)
我忘了在清单文件中声明位置权限。要以编程方式发现蓝牙设备，您需要添加两个权限，即ACCESS_LOCATION和ACCESS_COARSE。
答案 4 :(得分：0)
尝试使用此代码，它对我有用。
public class DeviceListActivity extends Activity {
private ListView pairedDevicesListView, newDevicesListView;
private ArrayList<DeviceData> dataList= new ArrayList<DeviceData>();
private ArrayList<BluetoothDevice> pairedDevices=new ArrayList<BluetoothDevice>();
private BluetoothAdapter bluetoothAdapter;
BluetoothDevice device;
private ArrayAdapter newDeviceAdapter;
private DeviceListAdapter pairedDeviceAdapter;
public static String DEVICE_ADDRESS = "device_address";
private IntentFilter filter;
private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
Log.e("action", action);
// Toast.makeText(DeviceListActivity.this, action, Toast.LENGTH_SHORT).show();
device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
if (action.equals(BluetoothDevice.ACTION_FOUND)) {
device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
newDeviceAdapter.add(device.getName() + "\n" + device.getAddress());
pairedDevices.add(device);
newDeviceAdapter.notifyDataSetChanged();
}
} else if (action.equals(BluetoothAdapter.ACTION_DISCOVERY_FINISHED)) {
if (newDeviceAdapter.getCount() == 0) {
Toast.makeText(DeviceListActivity.this, "No devices found", Toast.LENGTH_SHORT).show();
newDeviceAdapter.add("No new device found");
newDeviceAdapter.notifyDataSetChanged();
}
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_device_list);
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
pairedDevicesListView = (ListView) findViewById(R.id.avail_devices);
newDevicesListView=(ListView)findViewById(R.id.new_devices);
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
pairedDeviceAdapter = new DeviceListAdapter(this,dataList, pairedDevices);
pairedDevicesListView.setAdapter(pairedDeviceAdapter);
pairedDeviceAdapter.notifyDataSetChanged();
//-----------------------------------------------
newDeviceAdapter=new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1);
newDevicesListView.setAdapter(newDeviceAdapter);
newDeviceAdapter.notifyDataSetChanged();
if (bluetoothAdapter.isDiscovering()) {
bluetoothAdapter.cancelDiscovery();
}
bluetoothAdapter.startDiscovery();
// get paired devices
Set<BluetoothDevice> pairedDevice = bluetoothAdapter.getBondedDevices();
if(pairedDevice.size()>0)
{
// pairedDeviceAdapter.clear();
for(BluetoothDevice device : pairedDevice)
{
// pairedDeviceAdapter.add(device.getName()+ "\n" +device.getAddress());
dataList.add(new DeviceData(device.getName(),device.getAddress()));
pairedDevices.add(device);
}
pairedDeviceAdapter.notifyDataSetChanged();
}
// register broadcast receiver
filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(broadcastReceiver, filter);
pairedDevicesListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
bluetoothAdapter.cancelDiscovery();
String data = ((TextView) view).getText().toString();
String address = data.substring(data.length() - 17);
Intent intent = new Intent();
intent.putExtra("device_address", address);
intent.putExtra("info", data);
setResult(Activity.RESULT_OK, intent);
finish();
}
});
newDevicesListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
bluetoothAdapter.cancelDiscovery();
Boolean isBonded = false;
try {
isBonded = createBond(device);
if(isBonded)
{
Log.i("Log","Paired");
// pairedDeviceAdapter.add(device.getName() + "\n" + device.getAddress());
dataList.add(new DeviceData(device.getName(),device.getAddress()));
newDeviceAdapter.remove(device.getName() + "\n" + device.getAddress());
pairedDeviceAdapter.notifyDataSetChanged();
newDeviceAdapter.notifyDataSetChanged();
// Toast.makeText(DeviceListActivity.this, "paired to:" +device.getName(), Toast.LENGTH_SHORT).show();
// ------------------------
// Intent intent = new Intent();
// intent.putExtra("device_address", device.getAddress());
// intent.putExtra("info", device.getName());
// setResult(Activity.RESULT_OK, intent);
// finish();
}
} catch (Exception e)
{
e.printStackTrace();
}
}
});
}
@Override
protected void onStart() {
super.onStart();
registerReceiver(broadcastReceiver, filter);
}
@Override
protected void onPostResume() {
super.onPostResume();
registerReceiver(broadcastReceiver, filter);
}
@Override
protected void onDestroy() {
super.onDestroy();
if (bluetoothAdapter != null) {
bluetoothAdapter.cancelDiscovery();
}
this.unregisterReceiver(broadcastReceiver);
}
public boolean createBond(BluetoothDevice btDevice)
throws Exception
{
Class class1 = Class.forName("android.bluetooth.BluetoothDevice");
Method createBondMethod = class1.getMethod("createBond");
Boolean returnValue = (Boolean) createBondMethod.invoke(btDevice);
return returnValue.booleanValue();
}
}