I am new to android environment.I am trying to create a remote for a powerpoint for changing the slides.I used a Listview to display all the discovered bluetooth devices and implemented onItemClickListener and connected to the socket.But the problem is,when i fire another activity the connection is lost.I tried using service to hold the connection in all the activities, but couldn't succeed.Its throwing exceptions like "getBluetoothService() called with no bluetoothmanagercallback".The code which i've written for discovering and connecting bluetooth devices is:
package com.sowmithra.bluetoothclient;
import java.io.IOException;``
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.UUID;
import com.sowmithra.bluetoothclient.R;
import com.sowmithra.bluetoothclient.Main1.ConnectThread;
import android.app.Activity;
import android.app.Application;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
public class BluetoothTestActivity extends Activity {
/*
* (non-Javadoc)
*
* @see android.app.ListActivity#onListItemClick(android.widget.ListView,
* android.view.View, int, long)
*/
private static final int REQUEST_ENABLE_BT = 243;
/* (non-Javadoc)
* @see android.app.Activity#onResume()
*/
@Override
protected void onResume() {
connector=null;
check=false;
super.onResume();
}
/* (non-Javadoc)
* @see android.app.Activity#onStop()
*/
@Override
protected void onStop() {
connector.cancel();
super.onStop();
}
Intent intent;
private Set<BluetoothDevice> pairedDevices = null;
private BluetoothAdapter mbluetoothAdapter = null;
private Button bPaired = null;
private Button bDiscover = null;
private Button bStopDiscovery = null;
private Button bRemote=null;
private ArrayAdapter<Item> mpArrayAdpater = null;
private ArrayAdapter<Item> mdArrayAdpater = null;
private ListView pairedList = null;
private ListView discoveredList = null;
private List<Item> pSet = null;
private List<Item> dSet = null;
private boolean check = false;
private ConnectThread connector = null;
private BroadcastReceiver mReceiver = 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);
Item item = new Item(device.getName(), device);
mdArrayAdpater.add(item);
}
}
};
public static BluetoothDevice devname;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
bPaired = (Button) findViewById(R.id.bPaired);
bDiscover = (Button) findViewById(R.id.bDiscover);
bStopDiscovery=(Button)findViewById(R.id.bStop);
//these three to control slide motion
bRemote=(Button)findViewById(R.id.bRemote);
pairedList = (ListView) findViewById(R.id.listPaired);
discoveredList = (ListView) findViewById(R.id.listDiscovered);
pSet = new ArrayList<Item>();
dSet = new ArrayList<Item>();
mpArrayAdpater = new ArrayAdapter<Item>(getApplicationContext(),
android.R.layout.simple_list_item_1, pSet);
mdArrayAdpater = new ArrayAdapter<Item>(getApplicationContext(),
android.R.layout.simple_list_item_1, dSet);
pairedList.setAdapter(mpArrayAdpater);
discoveredList.setAdapter(mdArrayAdpater);
// Get Bluetooth device and enable it if not enabled
mbluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mbluetoothAdapter == null) {
Toast.makeText(getApplicationContext(),
"device donot support bluetooth ", Toast.LENGTH_LONG)
.show();
}
if (!mbluetoothAdapter.isEnabled()) {
Intent enableIntent = new Intent(
BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
}
// Button's onclickListener
bPaired.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
pairedDevices = mbluetoothAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
for (BluetoothDevice bdevice : pairedDevices) {
Item item = new Item(bdevice.getName(), bdevice);
mpArrayAdpater.add(item);
}
}
}
});
bDiscover.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
IntentFilter filter = new IntentFilter(
BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter);
mdArrayAdpater.clear();
mbluetoothAdapter.startDiscovery();
}
});
bRemote.setText("Start");
bRemote.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (check == true) {
bRemote.setText("Stop");
check = false;
} else {
bRemote.setText("Start");
if (connector != null)
connector.cancel();
check=true;
}
intent = new Intent(BluetoothTestActivity.this,Main1.class);
startActivity(intent);
}
});
bStopDiscovery.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mbluetoothAdapter.cancelDiscovery();
}
});
/*
* to make your device discoverable Intent discoverableIntent = new
* Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
* discoverableIntent
* .putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
* startActivity(discoverableIntent);
*/
// listView onItemClickListeners
pairedList
.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Item item = (Item) parent.getAdapter()
.getItem(position);
String texte = item.getDevName() + " "
+ item.getBdevice().getAddress();
Toast.makeText(getApplicationContext(), texte,
Toast.LENGTH_SHORT).show();
}
});
discoveredList
.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Item item = (Item) parent.getAdapter()
.getItem(position);
String texte = item.getDevName() + " "
+ item.getBdevice().getAddress();
Toast.makeText(getApplicationContext(), texte,
Toast.LENGTH_SHORT).show();
//If without disconnecting one tries to connect again
if(connector!=null)connector.cancel();
check=false;
bRemote.setText("Start");
//----------------------------------------------------
mbluetoothAdapter.cancelDiscovery();
devname = item.getBdevice();
connector = new ConnectThread(item.getBdevice());
connector.start();
new Intent(BluetoothTestActivity.this, ConnectionService.class);
startService(intent);
try {
Thread.sleep(2000, 0);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Toast.makeText(getApplicationContext(), "now start", Toast.LENGTH_SHORT).show();
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK && requestCode == REQUEST_ENABLE_BT) {
Toast.makeText(getApplicationContext(),
"Bluetooth enabled perfectly", Toast.LENGTH_SHORT).show();
}
}
// Needed for Adpater to able store more info and to have a proper view of
// B-devices
class Item {
String devName;
BluetoothDevice bdevice;
public Item(String devName, BluetoothDevice bdevice) {
super();
this.devName = devName;
this.bdevice = bdevice;
}
public String getDevName() {
return devName;
}
public void setDevName(String devName) {
this.devName = devName;
}
public BluetoothDevice getBdevice() {
return bdevice;
}
public void setBdevice(BluetoothDevice bdevice) {
this.bdevice = bdevice;
}
@Override
public String toString() {
// TODO Auto-generated method stub
return this.getDevName();
}
}
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
UUID uuid = UUID
.fromString("0f2b61c1-8be2-40e6-ab90-e735818da0a7");
tmp = mmDevice.createRfcommSocketToServiceRecord(uuid);
} catch (IOException e) {
}
mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
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)
manageConnectedSocket(mmSocket);
}
private void manageConnectedSocket(BluetoothSocket mmSocket2) {
//to get things start working set to true
check = true;
}
public BluetoothSocket getMmSocket() {
return mmSocket;
}
/** Will cancel an in-progress connection, and close the socket */
public void cancel() {``
try {
mmSocket.close();
} catch (IOException e) {
}
}
}
}
I want to switch to Main1.class but the connection is lost when i change the activity.Just explain how to use a service in this context.Any help would be appreciated.Thank you in advance.
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