我正在开发一个通过蓝牙将数据发送到所连接设备的应用程序。 作为参考，我复制了Google示例中的代码，并且有以下代码：
package in.justrobotics.jrbluetoothcontrol;
import android.Manifest;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothProfile;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.SystemClock;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Method;
import java.util.Set;
import java.util.UUID;
public class ControllerActivity extends AppCompatActivity {
// GUI Components
// private TextView mBluetoothStatus;
// private TextView mReadBuffer;
// private Button mScanBtn;
// private Button mOffBtn;
// private Button mListPairedDevicesBtn;
// private Button mDiscoverBtn;
private BluetoothAdapter mBTAdapter;
private Set<BluetoothDevice> mPairedDevices;
private ArrayAdapter<String> mBTArrayAdapter;
private ListView mDevicesListView;
private ImageView Up,Down,Left,Right;
private int commandFromForward,commandFromReverse,commandFromLeft,commandFromRight;
private final String TAG = MainActivity.class.getSimpleName();
private Handler mHandler; // Our main handler that will receive callback notifications
private ConnectedThread mConnectedThread; // bluetooth background worker thread to send and receive data
private BluetoothSocket mBTSocket = null; // bi-directional client-to-client data path
private static final UUID BTMODULEUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); // "random" unique identifier
// #defines for identifying shared types between calling functions
private final static int REQUEST_ENABLE_BT = 1; // used to identify adding bluetooth names
private final static int MESSAGE_READ = 2; // used in bluetooth handler to identify message update
private final static int CONNECTING_STATUS = 3; // used in bluetooth handler to identify message status
public String rBTaddress;
public String rBTname;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_controller);
Up = (ImageView) findViewById(R.id.upfwd);
Down = (ImageView) findViewById(R.id.downbk);
Left = (ImageView) findViewById(R.id.leftlt);
Right = (ImageView) findViewById(R.id.rightrt);
commandFromForward=0;
commandFromReverse=0;
commandFromLeft=0;
commandFromRight=0;
// mDevicesListView = (ListView)findViewById(R.id.devicesListView);
// mDevicesListView.setAdapter(mBTArrayAdapter); // assign model to view
// mDevicesListView.setOnItemClickListener(mDeviceClickListener);
mBTArrayAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1);
// Ask for location permission if not already allowed
if(ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED)
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, 1);
mHandler = new Handler(){
public void handleMessage(android.os.Message msg){
if(msg.what == MESSAGE_READ){
String readMessage = null;
try {
readMessage = new String((byte[]) msg.obj, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
// mReadBuffer.setText(readMessage);
}
if(msg.what == CONNECTING_STATUS){
if(msg.arg1 == 1){}
// mBluetoothStatus.setText("Connected to Device: " + (String)(msg.obj));
else{}
// mBluetoothStatus.setText("Connection Failed");
}
}
};
if (mBTArrayAdapter == null) {
// Device does not support Bluetooth
// mBluetoothStatus.setText("Status: Bluetooth not found");
Toast.makeText(getApplicationContext(),"Bluetooth device not found!",Toast.LENGTH_SHORT).show();
}
else {
/* Up.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
commandFromForward=1;
}
});
Down.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
commandFromReverse=2;
}
});
Left.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
commandFromLeft=4;
}
});
Right.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
commandFromRight=8;
if(mConnectedThread != null) //First check to make sure thread created
mConnectedThread.write(Integer.toString(commandFromRight));
}
});*/
checkConnected();
new Thread()
{
public void run() {
boolean fail = false;
BluetoothDevice mdevice = mBTAdapter.getRemoteDevice(rBTaddress);
try {
mBTSocket = createBluetoothSocket(mdevice);
} catch (IOException e) {
fail = true;
Toast.makeText(getBaseContext(), "Socket creation failed", Toast.LENGTH_SHORT).show();
}
// Establish the Bluetooth socket connection.
try {
mBTSocket.connect();
} catch (IOException e) {
try {
fail = true;
mBTSocket.close();
mHandler.obtainMessage(CONNECTING_STATUS, -1, -1)
.sendToTarget();
} catch (IOException e2) {
//insert code to deal with this
Toast.makeText(getBaseContext(), "Socket creation failed", Toast.LENGTH_SHORT).show();
}
}
if(fail == false) {
mConnectedThread = new ConnectedThread(mBTSocket);
mConnectedThread.start();
mHandler.obtainMessage(CONNECTING_STATUS, 1, -1, rBTname)
.sendToTarget();
}
}
}.start();
Up.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction()==MotionEvent.ACTION_DOWN){
commandFromForward=1;
}
if (event.getAction()==MotionEvent.ACTION_UP){
commandFromForward=0;
}
return false;
}
});
Down.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction()==MotionEvent.ACTION_DOWN){
commandFromReverse=2;
}
if (event.getAction()==MotionEvent.ACTION_UP){
commandFromReverse=0;
}
return false;
}
});
Left.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction()==MotionEvent.ACTION_DOWN){
commandFromLeft=4;
}
if (event.getAction()==MotionEvent.ACTION_UP){
commandFromLeft=0;
}
return false;
}
});
Right.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction()==MotionEvent.ACTION_DOWN){
commandFromRight=8;
}
if (event.getAction()==MotionEvent.ACTION_UP){
commandFromRight=0;
}
return false;
}
});
if (mConnectedThread != null) {
mConnectedThread.write("stdc_init");
}
else if (mConnectedThread==null) {
toastMe("It seems your bluetooth module is disconnected. Please connect it and restart.","long");
}
/*
mScanBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
bluetoothOn();
}
});
mOffBtn.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
bluetoothOff(v);
}
});
mListPairedDevicesBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v){
listPairedDevices(v);
}
});
mDiscoverBtn.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
discover(v);
}
});
*/
}
final Handler ha=new Handler();
ha.postDelayed(new Runnable() {
@Override
public void run() {
if (mConnectedThread != null) {
sendCumulativeCommand(commandFromForward,commandFromReverse,commandFromLeft,commandFromRight);
}
ha.postDelayed(this, 100);
}
}, 100);
}
public void toastMe(String toastMessage, String type){
if (type=="long") {
Toast.makeText(getApplicationContext(), toastMessage, Toast.LENGTH_LONG).show();
}
else if (type=="short") {
Toast.makeText(getApplicationContext(), toastMessage, Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(getApplicationContext(), toastMessage, Toast.LENGTH_SHORT).show();
}
/* try {
synchronized (this) {
this.wait(1000);
}
}
catch (InterruptedException ie){
System.out.println("Interrupted");
}*/
}
public void sendCumulativeCommand(int fd, int bk, int rt, int lt){
int cumulativeCommand=fd+bk+rt+lt;
mConnectedThread.write(Integer.toString(cumulativeCommand));
}
@Override
public boolean onCreateOptionsMenu (Menu menu){
getMenuInflater().inflate(R.menu.stdc_menu, menu);
return true;
}
public void checkConnected()
{
// true == headset connected && connected headset is support hands free
int state = BluetoothAdapter.getDefaultAdapter().getProfileConnectionState(BluetoothProfile.HEADSET);
if (state != BluetoothProfile.STATE_CONNECTED)
return;
try
{
BluetoothAdapter.getDefaultAdapter().getProfileProxy(getApplicationContext(), serviceListener, BluetoothProfile.HEADSET);
}
catch (Exception e)
{
e.printStackTrace();
}
}
private BluetoothProfile.ServiceListener serviceListener = new BluetoothProfile.ServiceListener()
{
@Override
public void onServiceDisconnected(int profile)
{
}
@Override
public void onServiceConnected(int profile, BluetoothProfile proxy)
{
for (BluetoothDevice device : proxy.getConnectedDevices())
{
rBTaddress=device.getAddress();
rBTname=device.getName();
Log.i("onServiceConnected", "|" + device.getName() + " | " + device.getAddress() + " | " + proxy.getConnectionState(device) + "(connected = "
+ BluetoothProfile.STATE_CONNECTED + ")");
}
BluetoothAdapter.getDefaultAdapter().closeProfileProxy(profile, proxy);
}
};
@Override
public boolean onOptionsItemSelected (MenuItem item){
int id = item.getItemId();
switch (id) {
case R.id.howtouse_controller:
displayAboutStandardController();
}
return true;
}
public void displayAboutStandardController() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("About the standard controller");
builder.setMessage(R.string.about_stdc);
builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
builder.show();
}
private void bluetoothOn(){
if (!mBTAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
// mBluetoothStatus.setText("Bluetooth enabled");
Toast.makeText(getApplicationContext(),"Bluetooth turned on",Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(getApplicationContext(),"Bluetooth is already on", Toast.LENGTH_SHORT).show();
}
}
// Enter here after user selects "yes" or "no" to enabling radio
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent Data){
// Check which request we're responding to
if (requestCode == REQUEST_ENABLE_BT) {
// Make sure the request was successful
if (resultCode == RESULT_OK) {
// The user picked a contact.
// The Intent's data Uri identifies which contact was selected.
// mBluetoothStatus.setText("Enabled");
}
else{}
// mBluetoothStatus.setText("Disabled");
}
}
private void bluetoothOff(View view){
mBTAdapter.disable(); // turn off
// mBluetoothStatus.setText("Bluetooth disabled");
Toast.makeText(getApplicationContext(),"Bluetooth turned Off", Toast.LENGTH_SHORT).show();
}
private void discover(View view){
// Check if the device is already discovering
if(mBTAdapter.isDiscovering()){
mBTAdapter.cancelDiscovery();
Toast.makeText(getApplicationContext(),"Discovery stopped",Toast.LENGTH_SHORT).show();
}
else{
if(mBTAdapter.isEnabled()) {
mBTArrayAdapter.clear(); // clear items
mBTAdapter.startDiscovery();
Toast.makeText(getApplicationContext(), "Discovery started", Toast.LENGTH_SHORT).show();
registerReceiver(blReceiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));
}
else{
Toast.makeText(getApplicationContext(), "Bluetooth not on", Toast.LENGTH_SHORT).show();
}
}
}
final BroadcastReceiver blReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if(BluetoothDevice.ACTION_FOUND.equals(action)){
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// add the name to the list
mBTArrayAdapter.add(device.getName() + "\n" + device.getAddress());
mBTArrayAdapter.notifyDataSetChanged();
}
}
};
private void listPairedDevices(View view){
mPairedDevices = mBTAdapter.getBondedDevices();
if(mBTAdapter.isEnabled()) {
// put it's one to the adapter
for (BluetoothDevice device : mPairedDevices)
mBTArrayAdapter.add(device.getName() + "\n" + device.getAddress());
Toast.makeText(getApplicationContext(), "Show Paired Devices", Toast.LENGTH_SHORT).show();
}
else
Toast.makeText(getApplicationContext(), "Bluetooth not on", Toast.LENGTH_SHORT).show();
}
private AdapterView.OnItemClickListener mDeviceClickListener = new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
if(!mBTAdapter.isEnabled()) {
Toast.makeText(getBaseContext(), "Bluetooth not on", Toast.LENGTH_SHORT).show();
return;
}
// mBluetoothStatus.setText("Connecting...");
// Get the device MAC address, which is the last 17 chars in the View
String info = ((TextView) v).getText().toString();
final String address = info.substring(info.length() - 17);
final String name = info.substring(0,info.length() - 17);
// Spawn a new thread to avoid blocking the GUI one
new Thread()
{
public void run() {
boolean fail = false;
BluetoothDevice mdevice = mBTAdapter.getRemoteDevice(address);
try {
mBTSocket = createBluetoothSocket(mdevice);
} catch (IOException e) {
fail = true;
Toast.makeText(getBaseContext(), "Socket creation failed", Toast.LENGTH_SHORT).show();
}
// Establish the Bluetooth socket connection.
try {
mBTSocket.connect();
} catch (IOException e) {
try {
fail = true;
mBTSocket.close();
mHandler.obtainMessage(CONNECTING_STATUS, -1, -1)
.sendToTarget();
} catch (IOException e2) {
//insert code to deal with this
Toast.makeText(getBaseContext(), "Socket creation failed", Toast.LENGTH_SHORT).show();
}
}
if(fail == false) {
mConnectedThread = new ConnectedThread(mBTSocket);
mConnectedThread.start();
mHandler.obtainMessage(CONNECTING_STATUS, 1, -1, name)
.sendToTarget();
}
}
}.start();
}
};
private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException {
try {
final Method m = device.getClass().getMethod("createInsecureRfcommSocketToServiceRecord", UUID.class);
return (BluetoothSocket) m.invoke(device, BTMODULEUUID);
} catch (Exception e) {
Log.e(TAG, "Could not create Insecure RFComm Connection",e);
}
return device.createRfcommSocketToServiceRecord(BTMODULEUUID);
}
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.available();
if(bytes != 0) {
buffer = new byte[1024];
SystemClock.sleep(100); //pause and wait for rest of data. Adjust this depending on your sending speed.
bytes = mmInStream.available(); // how many bytes are ready to be read?
bytes = mmInStream.read(buffer, 0, bytes); // record how many bytes we actually read
mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
.sendToTarget(); // Send the obtained bytes to the UI activity
}
} catch (IOException e) {
e.printStackTrace();
break;
}
}
}
/* Call this from the main activity to send data to the remote device */
public void write(String input) {
byte[] bytes = input.getBytes(); //converts entered String into 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) { }
}
}
}
但是，该示例所做的是让用户选择一个设备，然后用它建立一个ConnectedThread。
我想做的是事先拥有一个连接的设备（该设备将已经连接），并仅假定此连接的设备是所需的设备，然后与它建立一个ConnectedThread。为此，我认为我们需要连接的设备的特定地址。怎么办？
我尝试过
String name;
String address;
String threadName;
public void checkConnected()
{
BluetoothAdapter.getDefaultAdapter().getProfileProxy(this, serviceListener, BluetoothProfile.HEADSET);
}
private BluetoothProfile.ServiceListener serviceListener = new BluetoothProfile.ServiceListener()
{
@Override
public void onServiceDisconnected(int profile)
{
}
@Override
public void onServiceConnected(int profile, BluetoothProfile proxy)
{
for (BluetoothDevice device : proxy.getConnectedDevices())
{
name = device.getName();
address = device.getAddress();
threadName = Thread.currentThread().getName();
Toast.makeText(MainActivity.this, name+" " + address+ threadName, Toast.LENGTH_SHORT).show();
txtName.setText(name + " " + address);
Log.i("onServiceConnected", "|" + device.getName() + " | " + device.getAddress() + " | " + proxy.getConnectionState(device) + "(connected = "
+ BluetoothProfile.STATE_CONNECTED + ")");
}
BluetoothAdapter.getDefaultAdapter().closeProfileProxy(profile, proxy);
}
};
称为checkConnected（）;但我得到address为空。我在做什么错了？
谢谢。