我无法连接到远程蓝牙设备。我可以在 ListView 中看到配对和建立的设备，但是当我单击 ListView 中的项目(我的电脑或 Nexus 5 的名称)时，什么也没有发生。不出现蓝牙配对请求窗口。
Manifest.xml
<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
activity_main.xml
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="10dp">
<LinearLayout
android:layout_gravity="center_horizontal"
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<Button
android:id="@+id/button_enable_BT"
android:layout_marginRight="10dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/enableBT"/>
<Button
android:id="@+id/button_start_discovery"
android:layout_marginRight="10dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/start_discovery_button"/>
<Button
android:id="@+id/button_stop_discovery"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/stop_discovery_button"/>
</LinearLayout>
<TextView
android:id="@+id/status"
android:hint="@string/status"
android:layout_gravity="center_horizontal"
android:layout_marginTop="10dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginTop="10dp"
android:text="@string/paired_devices"/>
<ListView
android:id="@+id/paired_list"
android:layout_marginTop="10dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<LinearLayout
MainActivity.java
public class MainActivity extends Activity {
private final static int REQUEST_ENABLE_BT = 1;
private final static int REQUEST_COARSE_LOCATION_PERMISSIONS = 2;
UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
BluetoothAdapter mBluetoothAdapter;
ListView pairedList;
ListView newList;
Button mStart;
Button mStop;
Button mEnableBT;
TextView status;
ArrayAdapter<String> mArrayAdapter;
ArrayList<BluetoothDevice> devices;
IntentFilter filter;
String[] names;
ConnectThread mConnectThread;
ConnectedThread mConnectedThread;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
for (BluetoothDevice device : pairedDevices) {
devices.add(device);
mArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
}
pairedList.setAdapter(mArrayAdapter);
mStart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
doDiscovery();
}
});
mStop.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mBluetoothAdapter.cancelDiscovery();
}
});
mEnableBT.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
}
});
AdapterView.OnItemClickListener itemClickListener = new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if(mBluetoothAdapter.isDiscovering()){
mBluetoothAdapter.cancelDiscovery();
}
BluetoothDevice selectedDevice = devices.get(position);
mConnectThread = new ConnectThread(selectedDevice);
mConnectThread.start();
}
};
pairedList.setOnItemClickListener(itemClickListener);
filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter);
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
registerReceiver(mReceiver, filter);
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(mReceiver, filter);
filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
registerReceiver(mReceiver, filter);
}
@Override
protected void onDestroy() {
super.onDestroy();
mBluetoothAdapter.cancelDiscovery();
unregisterReceiver(mReceiver);
}
public void init(){
names = new String[10];
devices = new ArrayList<>();
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
status = (TextView)findViewById(R.id.status);
mStart = (Button)findViewById(R.id.button_start_discovery);
mStop = (Button)findViewById(R.id.button_stop_discovery);
mEnableBT = (Button)findViewById(R.id.button_enable_BT);
pairedList = (ListView)findViewById(R.id.paired_list);
mArrayAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1);
}
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if(BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)) {
int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, BluetoothAdapter.ERROR);
if(BluetoothAdapter.STATE_ON == state){
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
for (BluetoothDevice device : pairedDevices) {
mArrayAdapter.add(device.getName() + "\n" + device.getAddress());
devices.add(device);
}
}
}
if(BluetoothAdapter.STATE_OFF == state){
mArrayAdapter.clear();
devices.clear();
}
}
if(BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)){
status.setText("Discovery started");
}
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
status.setText("Device found");
if(device.getBondState() != BluetoothDevice.BOND_BONDED) {
if(mArrayAdapter.getPosition(device.getName()+"\n"+device.getAddress()) < 0){
mArrayAdapter.add(device.getName()+"\n"+device.getAddress());
devices.add(device);
status.setText("!!!");
}
}
}
if(BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)){
status.setText("Discovery stopped");
}
}
};
public void doDiscovery(){
int hasPermission = checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION);
if (hasPermission == PackageManager.PERMISSION_GRANTED) {
if(mBluetoothAdapter.isDiscovering()){
mBluetoothAdapter.cancelDiscovery();
}
mBluetoothAdapter.startDiscovery();
}
requestPermissions(new String[]{android.Manifest.permission.ACCESS_COARSE_LOCATION},
REQUEST_COARSE_LOCATION_PERMISSIONS);
}
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case REQUEST_COARSE_LOCATION_PERMISSIONS: {
if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
if(mBluetoothAdapter.isDiscovering()){
mBluetoothAdapter.cancelDiscovery();
}
mBluetoothAdapter.startDiscovery();
} else {
Toast.makeText(this,
getResources().getString(R.string.permission_failure),
Toast.LENGTH_LONG).show();
mBluetoothAdapter.cancelDiscovery();
}
return;
}
}
}
public synchronized void connected(BluetoothSocket socket) {
// Cancel the thread that completed the connection
if (mConnectThread != null) {
mConnectThread.cancel();
mConnectThread = null;
}
// Cancel any thread currently running a connection
if (mConnectedThread != null) {
mConnectedThread.cancel();
mConnectedThread = null;
}
// Start the thread to manage the connection and perform transmissions
mConnectedThread = new ConnectedThread(socket);
mConnectedThread.start();
}
private class ConnectThread extends Thread {
private final BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
public ConnectThread(BluetoothDevice device) {
// Use a temporary object that is later assigned to mmSocket,
// because mmSocket is final
BluetoothSocket tmp = null;
mmDevice = device;
// Get a BluetoothSocket to connect with the given BluetoothDevice
try {
// MY_UUID is the app's UUID string, also used by the server code
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) { }
mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
mBluetoothAdapter.cancelDiscovery();
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
} catch (IOException connectException) {
// Unable to connect; close the socket and get out
try {
mmSocket.close();
} catch (IOException closeException) { }
return;
}
// Do work to manage the connection (in a separate thread)
connected(mmSocket);
}
/** Will cancel an in-progress connection, and close the socket */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
}
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the input and output streams, using temp objects because
// member streams are final
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) { }
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
byte[] buffer = new byte[1024]; // buffer store for the stream
int bytes; // bytes returned from read()
// Keep listening to the InputStream until an exception occurs
while (true) {
try {
// Read from the InputStream
bytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI activity
} catch (IOException e) {
break;
}
}
}
/* Call this from the main activity to send data to the remote device */
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
} catch (IOException e) { }
}
/* Call this from the main activity to shutdown the connection */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
}
}
最佳答案
对于 6.0 (API 23) 及以上版本，现在您需要在运行时请求权限，仅在 list 上声明它们是不够的。因此，您需要执行以下操作:https://stackoverflow.com/a/33052902/2328012
希望对你有帮助!
关于java - 无法与远程设备进行蓝牙连接。安卓6.0，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36661680/