我制作了一个程序，可以将蓝牙连接到我的设备并从我的设备获取字节。 但该程序无法在后台运行。
我只想在后台获取字节。
我创建了另一个扩展Service并尝试让我的程序运行的类。
public class NickyService extends Service {
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent,flags,startId);
//Wrong code
MainActivity a1 = new MainActivity();
return START_NOT_STICKY;
}
}
我不知道解决这个问题。 我该如何解决这个大问题？
以下代码是对的！ 它可以获取字节并连接到设备，但不能在后台运行!!
MainActivity.java
package com.example.bluetooth10;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Set;
import java.util.UUID;
import org.apache.http.util.ByteArrayBuffer;
import android.app.Service;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Vibrator;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity {
// textview for connection status
ListView pairedListView;
private ArrayAdapter<String> mPairedDevicesArrayAdapter;
TextView sensorView0, title_paired_devices;
String paired = "";
Handler bluetoothIn;
private TextView connecting_str;
private TextView textView1;
final int handlerState = 0; // used to identify handler message
private BluetoothAdapter btAdapter = null;
private BluetoothSocket btSocket = null;
private ByteArrayBuffer baf1 = new ByteArrayBuffer(32);
String path = Environment.getExternalStorageDirectory().toString();
private ConnectedThread mConnectedThread;
private static final UUID BTMODULEUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); // SPP UUID service - this should work for most devices
private static String address; // String for MAC address
protected void onHandleIntent(Intent workIntent) {
// Gets data from the incoming Intent
String dataString = workIntent.getDataString();
// Do work here, based on the contents of dataString
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView1 = (TextView) findViewById(R.id.textView1);
title_paired_devices = (TextView) findViewById(R.id.title_paired_devices);
...
bluetoothIn = new Handler() {
public void handleMessage(android.os.Message msg) {
connecting_str.setText("Connection!!");
byte[] readBuf = (byte[]) msg.obj; // obj = buffer from connect thread
for (int i=0; i<msg.arg1; i++) {
baf1.append((byte)readBuf[i]);
if (baf1.length()>1){
String str1 = String.format("%02X",(byte)baf1.byteAt(baf1.length()-2));
String str2 = String.format("%02X",(byte)baf1.byteAt(baf1.length()-1));
if (str1.equals("01") && str2.equals("FF")){
int tmpb = (byte)baf1.byteAt(13);
baf1.clear();
}
}
}
}
int toInt( byte[] bytes ) {
int result = 0;
for (int i=0; i<bytes.length; i++) {
result = ( result << 8 ) - Byte.MIN_VALUE + (int) bytes[i];
}
return result;
}
};
btAdapter = BluetoothAdapter.getDefaultAdapter(); // get Bluetooth adapter
checkBTState();
}
private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException
{
return device.createRfcommSocketToServiceRecord(BTMODULEUUID);
//creates secure outgoing connecetion with BT device using UUID
}
public void onResume() {
super.onResume();
checkBTState();
btAdapter = BluetoothAdapter.getDefaultAdapter();
Set<BluetoothDevice> pairedDevices = btAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);//make title viewable
for (BluetoothDevice device : pairedDevices) {
if (!paired.equals("")) paired = paired + ",";
paired = paired + device.getName() + ";" + device.getAddress();
}
} else {
paired = "no devices paired";
}
String str0[] = paired.split(",");
String str1 = str0[0]; //pairedListView.getItemAtPosition(0).toString(); //Get MAC address from DeviceListActivity
String str2[] = str1.split(";");
address = str2[1]; //Get the MAC address from the DeviceListActivty via EXTRA
BluetoothDevice device = btAdapter.getRemoteDevice(address); //create device and set the MAC address
try {
btSocket = createBluetoothSocket(device);
} catch (IOException e) {
Toast.makeText(getBaseContext(), "Socket creation failed", Toast.LENGTH_LONG).show();
}
try {
btSocket.connect();
} catch (IOException e) {
try {
btSocket.close();
} catch (IOException e2) { }
}
mConnectedThread = new ConnectedThread(btSocket);
mConnectedThread.start();
}
public void onPause() {
super.onPause();
try {
btSocket.close(); //Don't leave Bluetooth sockets open when leaving activity
} catch (IOException e2) { }
}
private void checkBTState() {
btAdapter = BluetoothAdapter.getDefaultAdapter(); // CHECK THIS OUT THAT IT WORKS!!!
if(btAdapter==null) {
Toast.makeText(getBaseContext(), "Device does not support Bluetooth", Toast.LENGTH_SHORT).show();
finish();
} else {
if (!btAdapter.isEnabled()) {
//Prompt user to turn on Bluetooth
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, 1);
}
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
// ***********************************************************
// create new class for connect thread
// ***********************************************************
private class ConnectedThread extends Thread {
private final InputStream mmInStream;
private final OutputStream mmOutStream;
//creation of the connect thread
public ConnectedThread(BluetoothSocket socket) {
InputStream tmpIn = null;
OutputStream tmpOut = null;
try {
//Create I/O streams for connection
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) { }
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
byte[] buffer = new byte[40]; //The arduino is sending a small amount of data so a large buffer is not needed
int bytes;
// Keep looping to listen for received messages
while (true) {
try {
bytes = mmInStream.read(buffer); //read bytes from input buffer
bluetoothIn.obtainMessage(handlerState, bytes, -1, buffer).sendToTarget(); //Send message to handler
} catch (IOException e) {
break;
}
}
}
}
}