我需要在不同的活动中保持蓝牙连接，以便将命令发送到OBDII适配器。 SPA类是三个不同的活动之一，我需要保持蓝牙连接运行，而不是在切换到它时死亡，以便通过蓝牙发送命令。我已经知道使用服务是将BTHandler绑定到该服务的好方法，但我真的不知道我应该对服务做些什么？我应该将BTHandler放在MyService班级吗？
BTHandler.java
public class BTHandler {
public static final int STATE_NONE = 0; // we're doing nothing
public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection
public static final int STATE_CONNECTED = 3; // now connected to a remote device
final ArrayList<String> devices = new ArrayList();
private final Handler mHandler;
private BluetoothAdapter mAdapter;
private BluetoothDevice device;
private ConnectThread mConnectThread;
private ConnectedThread mConnectedThread;
private BluetoothSocket socket;
private String status;
private int mState;
private boolean connectionStatus = false;
public BTHandler(Context context, Handler handler) { // Konstruktor
mAdapter = BluetoothAdapter.getDefaultAdapter();
mHandler = handler;
}
public void write(String s) {
mConnectedThread.sendRawCommand(s);
Log.v("write", "write");
}
/*
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
} catch (IOException e) {
}
}
*/
public void connect(String deviceAddress) {
mConnectThread = new ConnectThread(deviceAddress);
mConnectThread.start();
}
private void guiHandler(int what, int arg1, String obj) {
Message msg = mHandler.obtainMessage();
msg.what = what;
msg.obj = obj;
msg.arg1 = arg1;
msg.sendToTarget();
}
private class ConnectThread extends Thread {
BluetoothSocket tmp = null;
private BluetoothSocket mmSocket;
public ConnectThread(String deviceAddress) {
mAdapter = BluetoothAdapter.getDefaultAdapter();
device = mAdapter.getRemoteDevice(deviceAddress);
BluetoothAdapter mAdapter = BluetoothAdapter.getDefaultAdapter();
BluetoothDevice device = mAdapter.getRemoteDevice(deviceAddress);
UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
try {
tmp = device.createRfcommSocketToServiceRecord(uuid);
//socket.connect();
//Log.v("connect", "connect");
} catch (IOException e) {
//e.printStackTrace();
//Log.v("exception", "e");
}
mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
mAdapter.cancelDiscovery();
byte[] buffer = new byte[1024]; // buffer store for the stream
int bytes;
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
Log.v("connect", "connect");
} catch (IOException connectException) {
// Unable to connect; close the socket and get out
try {
mmSocket.close();
Log.v("close", "close");
} catch (IOException closeException) {
}
guiHandler(Constants.TOAST, Constants.SHORT, "Connection Failed");
return;
}
guiHandler(Constants.CONNECTION_STATUS, Constants.STATE_CONNECTED, "");
mConnectedThread = new ConnectedThread(mmSocket);
mConnectedThread.start();
}
}
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
private ObdMultiCommand multiCommand;
public ConnectedThread(BluetoothSocket socket) {
connectionStatus = true;
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
}
mmInStream = tmpIn;
mmOutStream = tmpOut;
try {
//RPMCommand engineRpmCommand = new RPMCommand();
//SpeedCommand speedCommand = new SpeedCommand();
ModuleVoltageCommand voltageCommand = new ModuleVoltageCommand();
while (!Thread.currentThread().isInterrupted()) {
//engineRpmCommand.run(mmInStream, mmOutStream); //(socket.getInputStream(), socket.getOutputStream());
//speedCommand.run(mmInStream, mmOutStream); //(socket.getInputStream(), socket.getOutputStream());
voltageCommand.run(socket.getInputStream(), socket.getOutputStream());
// TODO handle commands result
//Log.d("Log", "RPM: " + engineRpmCommand.getFormattedResult());
//Log.d("Log", "Speed: " + speedCommand.getFormattedResult());
Log.v("Log", "Voltage: " + voltageCommand.getFormattedResult());
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void run() {
byte[] buffer = new byte[1024]; // buffer store for the stream
int bytes; // bytes returned from read()
OBDcmds();
// Keep listening to the InputStream until an exception occurs
while (connectionStatus) {
sendMultiCommand();
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
// CALL this to MainActivity
public void sendRawCommand(String command) {
try {
new OdbRawCommand(command);
} catch (Exception e) {
Log.v("sendRawCommand", "e");
}
}
private void OBDcmds() { // execute commands
try {
new EchoOffCommand().run(socket.getInputStream(), socket.getOutputStream());
new LineFeedOffCommand().run(socket.getInputStream(), socket.getOutputStream());
new TimeoutCommand(100).run(socket.getInputStream(), socket.getOutputStream());
new SelectProtocolCommand(ObdProtocols.AUTO).run(socket.getInputStream(), socket.getOutputStream()); //ISO_15765_4_CAN
} catch (Exception e) {
Log.v("OBDcmds", "e");
// handle errors
}
}
/*
// 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) {
}
}
public void sendMultiCommand() {
try {
// RUN some code here
} catch (Exception e) {
}
}
}
}
MyService.java
public class MyService extends Service {
public MyService() {
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onCreate() {
Toast.makeText(this, "The new Service was Created", Toast.LENGTH_LONG).show();
}
@Override
public void onStart(Intent intent, int startId) {
// For time consuming an long tasks you can launch a new thread here...
// Do your Bluetooth Work Here
Toast.makeText(this, " Service Started", Toast.LENGTH_LONG).show();
}
@Override
public void onDestroy() {
Toast.makeText(this, "Service Destroyed", Toast.LENGTH_LONG).show();
}
}
SPA.java
public class SPA extends AppCompatActivity implements View.OnClickListener {
Button b2;
BTHandler btHandler;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
startService(new Intent(this, MyService.class));
setContentView(R.layout.activity_sp);
b2 = (Button) findViewById(R.id.getValue);
b2.setOnClickListener(this);
}
public void onClick(View v) {
int id = v.getId();
String voltage = ("AT RV");
switch (id) {
case R.id.getValue:
btHandler.write(voltage);
Log.v("Log", "getValue" + voltage);
break;
}
}
}