嗨，我想编写一个可以与蓝牙设备连接的 Android java 应用程序，但出现错误：
W/BluetoothAdapter﹕ getBluetoothService() called with no BluetoothManagerCallback
我使用 Nexus 5 设备，Android 版本为 4.4.4
这是我的代码：
package com.example.tarasov.bluetoothexample;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Set;
import java.util.UUID;
import android.view.Menu;
import android.view.MenuItem;
import android.app.Activity;
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.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class MyActivity extends Activity implements OnItemClickListener {
/*
* Deklaration
* */
ArrayAdapter<String> listAdapter;
ListView listView;
BluetoothAdapter btAdapter;
Set<BluetoothDevice> deviceArray;
ArrayList<String> pairedDevices;
ArrayList<BluetoothDevice> devices;
public static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
protected static final int SUCCESS_CONNECT = 0;
protected static final int MESSAGE_READ = 1;
IntentFilter filter;
BroadcastReceiver receiver;
String tag = "debugging";
Handler mHandler = new Handler(){
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
Log.i(tag, "in handler");
super.handleMessage(msg);
switch(msg.what){
case SUCCESS_CONNECT:
// DO something
ConnectedThread connectedThread = new ConnectedThread((BluetoothSocket)msg.obj);
Toast.makeText(getApplicationContext(), "CONNECT", Toast.LENGTH_SHORT).show();
String s = "successfully connected";
connectedThread.write(s.getBytes());
Log.i(tag, "connected");
break;
case MESSAGE_READ:
byte[] readBuf = (byte[])msg.obj;
String string = new String(readBuf);
Toast.makeText(getApplicationContext(), string, Toast.LENGTH_SHORT).show();
break;
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
init(); //Initialisierung der Komponenten
if(btAdapter==null)
{
Toast.makeText(getApplicationContext(), "Kein Bluetooth aktiviert", Toast.LENGTH_SHORT).show();
finish();
}
else
{
if (!btAdapter.isEnabled()){
turnOnBT();
}
getPairedDevices();
startDiscovery();
}
}
private void startDiscovery() {
btAdapter.cancelDiscovery();
btAdapter.startDiscovery();
}
private void turnOnBT() {
Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(intent,1);
}
private void getPairedDevices() {
deviceArray = btAdapter.getBondedDevices();
if (deviceArray.size()>0){
for (BluetoothDevice device:deviceArray){
pairedDevices.add(device.getName());
}
}
}
private void init(){
listView = (ListView)findViewById(R.id.listView); //bindet ListView
listView.setOnItemClickListener(this);
listAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,0);
listView.setAdapter(listAdapter);
btAdapter = BluetoothAdapter.getDefaultAdapter();
pairedDevices = new ArrayList<String>();
filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
devices = new ArrayList<BluetoothDevice>();
receiver = 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);
devices.add(device);
String s = "";
for (int a=0;a< pairedDevices.size();a++){
if (device.getName().equals(pairedDevices.get(a))){
s = "(Verbunden)";
break;
}
}
listAdapter.add(device.getName()+" "+s+" "+"\n"+device.getAddress());
}
else if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)){
}
else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)){
}
else if (BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)){
if (btAdapter.getState()==btAdapter.STATE_OFF){
turnOnBT();
}
}
}
};
registerReceiver(receiver,filter);
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
registerReceiver(receiver,filter);
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(receiver,filter);
filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
registerReceiver(receiver,filter);
}
@Override
protected void onPause() {
super.onPause();
unregisterReceiver(receiver);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode==RESULT_CANCELED){
Toast.makeText(getApplicationContext(), "Bluetooth muss erst aktiviert werden", Toast.LENGTH_SHORT).show();
finish();
}
}
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
if (btAdapter.isDiscovering()){
btAdapter.cancelDiscovery();
}
if (listAdapter.getItem(arg2).contains("Verbunden")){
BluetoothDevice selectedDevice = devices.get(arg2);
ConnectThread connect = new ConnectThread(selectedDevice);
connect.start();
Log.i(tag, "in click listener");
}
else
{
Toast.makeText(getApplicationContext(), "Gerät ist nicht verbunden", Toast.LENGTH_SHORT).show();
}
}
/*
* Hilfsklassen
* */
private 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;
Log.i(tag, "construct");
// Get a BluetoothSocket to connect with the given BluetoothDevice
try {
// MY_UUID is the app's UUID string, also used by the server code
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) {
Log.i(tag, "get socket failed");
}
mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
btAdapter.cancelDiscovery();
Log.i(tag, "connect - run");
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
Log.i(tag, "connect - succeeded");
} catch (IOException connectException) { Log.i(tag, "connect failed");
// 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)
mHandler.obtainMessage(SUCCESS_CONNECT, mmSocket).sendToTarget();
}
/** Will cancel an in-progress connection, and close the socket */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
}
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; // 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
buffer = new byte[1024];
bytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI activity
mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
} catch (IOException e) {
break;
}
}
}
/* 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) { }
}
}