我正试图通过我正在处理的应用程序连接到附近的蓝牙设备。
以下是我的 MainActivity.java [更新]
package vertex2016.mvjce.edu.bluealert;
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.content.pm.ActivityInfo;
import android.os.Bundle;
import android.os.Handler;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Gravity;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.*;
import java.io.IOException;
import java.util.UUID;
import static java.lang.Thread.sleep;
public class MainActivity extends AppCompatActivity {
//To get the default Bluetooth adapter on the Android device
public BluetoothAdapter BA = BluetoothAdapter.getDefaultAdapter();
//A request code to identify which activity was executed
private int REQ_CODE = 1;
private int backPressedCount;
private boolean on = false;
//The Search button on the main screen
private Button searchButton;
//The View that lists all the nearby Bluetooth devices found
private ListView listBTDevices;
private UUID myUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
//Store the recently found Bluetooth devices & pass them on to the ListView
private ArrayAdapter BTArrayAdapter;
//A variable that points to the actual Bluetooth on the device
private BluetoothDevice btd;
private BluetoothSocket bSocket;
//Container for the TextViews
private ViewGroup containerVG;
//UUID to specify the services it can provide
//Intent Filter to detect the discovery of nearby Bluetooth devices
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
//Lock the rotation of the screen
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
searchButton = (Button) findViewById(R.id.searchButton);
listBTDevices = (ListView) findViewById(R.id.listBTDevices);
backPressedCount = 1;
containerVG = (ViewGroup) findViewById(R.id.containerVG);
searchButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!on) {
connect();
} else if (on) {
stopDiscovery();
on = false;
searchButton.setText("Search");
}
}
});
listBTDevices.setOnItemClickListener(clickListener);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
//A method that checks if targeted device supports Bluetoth or not
//In case it does, execute the SearchBTDevices method to search
public void connect() {
//Registering the IntentFilter
this.registerReceiver(receiver, filter);
//If the device doesn't have Bluetooth, the Bluetooth Adapter BA returns NULL
if (BA == null)
Toast.makeText(MainActivity.this, "System Doesn't Support Bluetooth", Toast.LENGTH_SHORT).show();
//In case the device has Bluetooth, but Bluetooth isn't enabled
//Enables the Bluetooth on the device
//startActivityForResult() takes in the Intent & a REQUEST CODE to specifically identify that intent
else if (!BA.isEnabled()) {
Intent enableBT = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBT, REQ_CODE);
}
//In case Bluetooth is enabled on the device, start the discovery
else {
searchBTDevices();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode != RESULT_CANCELED) {
Toast.makeText(MainActivity.this, "TURNED ON!", Toast.LENGTH_SHORT).show();
searchBTDevices();
} else
Toast.makeText(MainActivity.this, "FAILED TO ENABLE BLUETOOTH", Toast.LENGTH_LONG).show();
}
public void searchBTDevices() {
//As soon as the search starts, the Welcome screen TextView disappears & ListView appears
containerVG.setVisibility(View.GONE);
listBTDevices.setVisibility(View.VISIBLE);
BTArrayAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1);
//In case the discovery fails to begin
if (!BA.startDiscovery())
Toast.makeText(MainActivity.this, "Failed to start discovery", Toast.LENGTH_SHORT).show();
else {
Toast.makeText(MainActivity.this, "Discovery Started", Toast.LENGTH_SHORT).show();
on = true;
searchButton.setText("Stop Discovery");
}
listBTDevices.setAdapter(BTArrayAdapter);
//Setting the onItemClick for selecting a Bluetooth device to connect to
}
private final BroadcastReceiver receiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
btd = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); //Get the device details
BTArrayAdapter.add(btd.getName() + "\t\t" + btd.getAddress());
}
}
};
private void stopDiscovery() {
BA.cancelDiscovery();
Toast.makeText(MainActivity.this, "Discovery Stopped", Toast.LENGTH_SHORT).show();
this.unregisterReceiver(receiver);
}
@Override
protected void onStop()
{
super.onStop();
BTArrayAdapter.clear();
}
@Override
protected void onResume() {
super.onResume();
BA.cancelDiscovery();
BA.startDiscovery();
}
@Override
protected void onRestart() {
super.onRestart();
Toast.makeText(MainActivity.this, "Discovery Resumed", Toast.LENGTH_SHORT).show();
}
public final AdapterView.OnItemClickListener clickListener = new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
/*
Intent connectedBT = new Intent(MainActivity.this, Connected.class);
connectedBT.putExtra("Bluetooth Device", btd);
startActivity(connectedBT);
*/
new ConnectingThread(btd).start();
}
};
@Override
public void onBackPressed() {
if (backPressedCount == 2) {
super.onBackPressed();
return;
}
else {
backPressedCount++;
Toast.makeText(this,"Press BACK again to exit", Toast.LENGTH_SHORT).show();
}
}
public class ConnectingThread extends Thread{
private final BluetoothDevice bluetoothDevice;
private final BluetoothSocket bluetoothSocket;
boolean ConnectionFlag = false;
public ConnectingThread(BluetoothDevice btd)
{
BluetoothSocket temp = null;
bluetoothDevice = btd;
try {
temp = btd.createInsecureRfcommSocketToServiceRecord(myUUID);
} catch (IOException e) {
e.printStackTrace();
}
bluetoothSocket = temp;
}
public void run()
{
BA.cancelDiscovery();
try {
Toast.makeText(MainActivity.this,"REACHED BEFORE SOCKET CONNECTION", Toast.LENGTH_SHORT).show();
System.out.println("#####THIS IS BEFORE SOCKET CONNECT#####");
bluetoothSocket.connect();
System.out.println("#####THIS IS AFTER SOCKET CONNECT#####");
Toast.makeText(MainActivity.this,"REACHED AFTER SOCKET CONNECTION", Toast.LENGTH_SHORT).show();
ConnectionFlag = true;
} catch (IOException e) {
try {
bluetoothSocket.close();
} catch (IOException e1) {
e1.printStackTrace();}
return;
}
if(ConnectionFlag)
Toast.makeText(MainActivity.this, "Connected to" + bluetoothDevice.getName(),Toast.LENGTH_SHORT).show();
else
Toast.makeText(MainActivity.this, "Failed to connect",Toast.LENGTH_SHORT).show();
}
}
}
这里发生了什么，
<{1}}之前的行System.out.println("#####THIS IS BEFORE SOCKET CONNECT#####");正在执行。
但之后的行bluetoothSocket.connect();永远不会被执行。
我最终在我的logcat中收到以下消息：
System.out.println("#####THIS IS AFTER SOCKET CONNECT#####");更新了logcat 消息
获得一些
07-13 17:47:33.482 32466-32466/vertex2016.mvjce.edu.bluealert I/Timeline: Timeline: Activity_idle id: android.os.BinderProxy@19e8271a time:59429753
07-13 17:48:16.276 32466-32466/vertex2016.mvjce.edu.bluealert I/System.out: #####THIS IS BEFORE SOCKET CONNECT#####
07-13 17:48:16.276 32466-32466/vertex2016.mvjce.edu.bluealert W/BluetoothAdapter: getBluetoothService() called with no BluetoothManagerCallback
07-13 17:48:22.789 32466-32466/vertex2016.mvjce.edu.bluealert I/Choreographer: Skipped 392 frames! The application may be doing too much work on its main thread.
07-13 17:48:22.889 32466-32466/vertex2016.mvjce.edu.bluealert I/System.out: #####THIS IS BEFORE SOCKET CONNECT#####
07-13 17:48:22.889 32466-32466/vertex2016.mvjce.edu.bluealert W/BluetoothAdapter: getBluetoothService() called with no BluetoothManagerCallback
07-13 17:48:29.415 32466-32466/vertex2016.mvjce.edu.bluealert I/Choreographer: Skipped 392 frames! The application may be doing too much work on its main thread.
这次和我之前的情况一样。
07-14 12:24:23.559 25623-25662/? E/bt-btif: DISCOVERY_COMP_EVT slot id:7, failed to find channle,status:1, scn:0答案 0 :(得分：0)
您不应该在Thread中执行run()。这不会创建一个合适的线程，而只是在标准类中运行run() - 方法。
相反，你应该调用start() - 方法“，它创建一个调用run() - 方法的线程。”
有关详细信息，请参阅以下链接：When would you call java's thread.run() instead of thread.start()?
因此您的代码将是：
new ConnectingThread(btd).start();