我正在开发设备和ECU（电子电路单元）之间的蓝牙应用。我使用服务类来建立后台服务以维护设备和ecu上的连接，即使从多任务中删除应用程序后我也需要连接。现在连接在删除后丢失了。可以做些什么？请帮我。
这是代码段
公共类IgnitionServicestart扩展了Service {
private static final String TAG = IgnitionServicestart.class.getSimpleName();
public static boolean isDeviceConnected = false;
// Name of the connected device
private static String mConnectedDeviceName = null;
// Array adapter for the conversation thread
private ArrayAdapter<String> mConversationArrayAdapter;
// String buffer for outgoing messages
private StringBuffer mOutStringBuffer = null;
// Local Bluetooth adapter
private BluetoothAdapter mBluetoothAdapter = null;
// Member object for the chat services
public static BluetoothChatService mChatService = null;
public static Context context;
@Override
public void onCreate() {
// Start up the thread running the service. Note that we create a
// separate thread because the service normally runs in the process's
// main thread, which we don't want to block. We also make it
// background priority so CPU-intensive work will not disrupt our UI.
// Get the HandlerThread's Looper and use it for our Handler
context=IgnitionServicestart.this;
handlerKeepAlive = new Handler();
handlerDisconnectBluetooth = new Handler();
mNotManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
setupChat();
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(Integer.toString(BluetoothChatService.STATE_CONNECTED));
intentFilter.addAction(Integer.toString(BluetoothChatService.STATE_NONE));
registerReceiver(bluetoothConnectionStatus, intentFilter);
if (!Config.BLUETOOTH) {
KeepAliveResponse objKeepAliveResponse = new KeepAliveResponse(
mHandler);
objKeepAliveResponse.start();
}
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
//Toast.makeText(this, "service starting", Toast.LENGTH_SHORT).show();
// For each start request, send a message to start a job and deliver the
// start ID so we know which request we're stopping when we finish the job
// If we get killed, after returning from here, restart
//context=IgnitionServicestart.this;
return START_NOT_STICKY;
}
@SuppressLint("NewApi")
private void setupChat() {
if (Config.LOGGING) {
Log.d(TAG, "setupChat()");
}
// Initialize the BluetoothChatService to perform bluetooth connections
if (Config.BLUETOOTH) {
if(mChatService == null)
mChatService = new BluetoothChatService(this, mHandler);
}
//}
// Initialize the buffer for outgoing messages
mOutStringBuffer = new StringBuffer("");
}
// The Handler that gets information back from the BluetoothChatService
private final static Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MESSAGE_STATE_CHANGE:
if (Config.LOGGING) {
Log.i(TAG, "MESSAGE_STATE_CHANGE: " + msg.arg1);
}
switch (msg.arg1) {
case BluetoothChatService.STATE_CONNECTED:
// mTitle.setText(R.string.title_connected_to);
// mTitle.append(mConnectedDeviceName);
// mConversationArrayAdapter.clear();
// Toast.makeText(getApplicationContext(),
// R.string.title_connected_to+mConnectedDeviceName,
// Toast.LENGTH_SHORT).show();
isDeviceConnected = true;
nKeepAliveReqCount = 0;
nKeepAliveResCount = 0;
// Start sending Keep Alive messages.
//handlerKeepAlive.removeCallbacks(SendKeepAliveMessage);
//handlerKeepAlive.postDelayed(SendKeepAliveMessage, Config.KEEP_ALIVE_INTERVAL);
context.sendBroadcast(new Intent(Integer.toString(BluetoothChatService.STATE_CONNECTED)));
break;
case BluetoothChatService.STATE_CONNECTING:
// mTitle.setText(R.string.title_connecting);
Toast.makeText(context,
R.string.title_connecting, Toast.LENGTH_SHORT)
.show();
break;
case BluetoothChatService.STATE_LISTEN:
case BluetoothChatService.STATE_NONE:
// mTitle.setText(R.string.title_not_connected);
// Toast.makeText(getApplicationContext(),
// R.string.title_not_connected, Toast.LENGTH_SHORT).show();
isDeviceConnected = false;
context.sendBroadcast(new Intent(Integer.toString(BluetoothChatService.STATE_NONE)));
break;
}
break;
case MESSAGE_WRITE:
byte[] writeBuf = (byte[]) msg.obj;
// construct a string from the buffer
/*
* String hexstring1=getHex(writeBuf);
* writeBuf=hexstring1.getBytes();
*/
String writeMessage = new String(writeBuf);
if (Config.LOGGING) {
Log.d("String Message", writeMessage);
}
// mConversationArrayAdapter.add("Me: " + writeMessage);
break;
case MESSAGE_READ:
// mTitle.setVisibility(View.VISIBLE);
byte[] readBuf = (byte[]) msg.obj;
// construct a string from the valid bytes in the buffer
String readMessage = new String(readBuf, 0, msg.arg1);
if (Config.LOGGING) {
Log.d("String Message", readMessage);
}
// mConversationArrayAdapter.add(mConnectedDeviceName + ": " + readMessage);
processReceivedMessage(readBuf);
break;
case MESSAGE_DEVICE_NAME:
// save the connected device's name
if (Config.BLUETOOTH) {
mConnectedDeviceName = msg.getData().getString(DEVICE_NAME);
Toast.makeText(context,
"Connected to " + mConnectedDeviceName,
Toast.LENGTH_SHORT).show();
}
break;
case MESSAGE_TOAST:
/********* COMMENTED CODE TO BE USED WHILE DEBUGGING ON DEVICE - BEGIN ***********/
// if (Config.INTERNAL) {
// Toast.makeText(MenuActivity.this,
// msg.getData().getString(TOAST), Toast.LENGTH_LONG)
// .show();
// }
/********* COMMENTED CODE TO BE USED WHILE DEBUGGING ON DEVICE - END ***********/
break;
case MESSAGE_ALERT:
/********* COMMENTED CODE TO BE USED WHILE DEBUGGING ON DEVICE - BEGIN ***********/
// if (Config.INTERNAL) {
// for (int i = 0; i < 5; i++) {
// Toast.makeText(MenuActivity.this,
// msg.getData().getString(TOAST),
// Toast.LENGTH_LONG).show();
// }
// }
/********* COMMENTED CODE TO BE USED WHILE DEBUGGING ON DEVICE - END ***********/
break;
}
}
};
/**
* Sends a message.
*
* @param message
* A string of text to send.
*/
public static void sendMessage(char[] message) {
// Check that we're actually connected before trying anything
if (Config.BLUETOOTH) {
if (mChatService.getState() != BluetoothChatService.STATE_CONNECTED) {
Toast.makeText(context, R.string.not_connected, Toast.LENGTH_SHORT).show();
return;
}
}
Toast.makeText(context, "inside send message"+message.toString(), Toast.LENGTH_SHORT).show();
// Check that there's actually something to send
if (message.length > 0) {
// Get the message bytes and tell the BluetoothChatService to write
byte[] send = new byte[message.length];
for (int i = 0; i < message.length; i++) {
send[i] = (byte) message[i];
}
if (Config.BLUETOOTH) {
mChatService.write(send);
}
// Reset out string buffer to zero and clear the edit text field
//mOutStringBuffer.setLength(0);
// mOutEditText.setText(mOutStringBuffer);
}
}
private BroadcastReceiver bluetoothConnectionStatus = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(context, "receiver", Toast.LENGTH_SHORT).show();
if (intent.getAction().equalsIgnoreCase(Integer.toString(BluetoothChatService.STATE_CONNECTED))) {
Toast.makeText(context, "connected receiver", Toast.LENGTH_SHORT).show();
}
else if (intent.getAction().equalsIgnoreCase(Integer.toString(BluetoothChatService.STATE_NONE))) {
Toast.makeText(context, "disconnected receiver", Toast.LENGTH_SHORT).show();
}
}
};
@Override
public IBinder onBind(Intent intent) {
return null;
}
}