کار با بلوتوث در اندروید

private BluetoothAdapter BA;
BA = BluetoothAdapter.getDefaultAdapter();

Intent turnOn = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(turnOn, 0);     

private Set<BluetoothDevice>pairedDevices;
pairedDevices = BA.getBondedDevices();

package com.example.sairamkrishna.myapplication;

import android.app.Activity;

import android.bluetooth.BluetoothAdapter;

import android.bluetooth.BluetoothDevice;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.graphics.Color;

import android.net.wifi.ScanResult;

import android.net.wifi.WifiManager;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.ArrayAdapter;

import android.widget.Button;

import android.widget.EditText;

import android.widget.ListView;

import android.widget.TextView;

import android.widget.Toast;

import java.util.ArrayList;

import java.util.List;

import java.util.Set;

public class MainActivity extends Activity  {

   Button b1,b2,b3,b4;

   private BluetoothAdapter BA;

   private Set<BluetoothDevice>pairedDevices;

   ListView lv;

   @Override

   protected void onCreate(Bundle savedInstanceState) {

      super.onCreate(savedInstanceState);

      setContentView(R.layout.activity_main);

      b1 = (Button) findViewById(R.id.button);

      b2=(Button)findViewById(R.id.button2);

      b3=(Button)findViewById(R.id.button3);

      b4=(Button)findViewById(R.id.button4);

      BA = BluetoothAdapter.getDefaultAdapter();

      lv = (ListView)findViewById(R.id.listView);

   }

   public void on(View v){

      if (!BA.isEnabled()) {

         Intent turnOn = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);

         startActivityForResult(turnOn, 0);

         Toast.makeText(getApplicationContext(),"Turned on",Toast.LENGTH_LONG).show();

      }

      else

      {

         Toast.makeText(getApplicationContext(),"Already on", Toast.LENGTH_LONG).show();

      }

   }

   public void off(View v){

      BA.disable();

      Toast.makeText(getApplicationContext(),"Turned off" ,Toast.LENGTH_LONG).show();

   }

   public  void visible(View v){

      Intent getVisible = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);

      startActivityForResult(getVisible, 0);

   }

   public void list(View v){

      pairedDevices = BA.getBondedDevices();

      ArrayList list = new ArrayList();

      for(BluetoothDevice bt : pairedDevices)

      list.add(bt.getName());

      Toast.makeText(getApplicationContext(),"Showing Paired Devices",Toast.LENGTH_SHORT).show();

      final ArrayAdapter adapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1, list);

      lv.setAdapter(adapter);

   }

   @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);

   }

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

   xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"

   android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"

   android:paddingRight="@dimen/activity_horizontal_margin"

   android:paddingTop="@dimen/activity_vertical_margin"

   android:paddingBottom="@dimen/activity_vertical_margin"

   tools:context=".MainActivity"

   android:transitionGroup="true">

   <TextView android:text="Bluetooth Example" android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:id="@+id/textview"

      android:textSize="35dp"

      android:layout_alignParentTop="true"

      android:layout_centerHorizontal="true" />

   <TextView

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:text="Tutorials point"

      android:id="@+id/textView"

      android:layout_below="@+id/textview"

      android:layout_centerHorizontal="true"

      android:textColor="#ff7aff24"

      android:textSize="35dp" />

   <ImageView

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:id="@+id/imageView"

      android:src="@drawable/abc"

      android:layout_below="@+id/textView"

      android:layout_centerHorizontal="true"

      android:theme="@style/Base.TextAppearance.AppCompat" />

   <Button

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:text="Turn On"

      android:id="@+id/button"

      android:layout_below="@+id/imageView"

      android:layout_toStartOf="@+id/imageView"

      android:layout_toLeftOf="@+id/imageView"

      android:clickable="true"

      android:onClick="on" />

   <Button

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:text="Get visible"

      android:onClick="visible"

      android:id="@+id/button2"

      android:layout_alignBottom="@+id/button"

      android:layout_centerHorizontal="true" />

   <Button

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:text="List devices"

      android:onClick="list"

      android:id="@+id/button3"

      android:layout_below="@+id/imageView"

      android:layout_toRightOf="@+id/imageView"

      android:layout_toEndOf="@+id/imageView" />

   <Button

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:text="turn off"

      android:onClick="off"

      android:id="@+id/button4"

      android:layout_below="@+id/button"

      android:layout_alignParentLeft="true"

      android:layout_alignParentStart="true" />

   <ListView

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:id="@+id/listView"

      android:layout_alignParentBottom="true"

      android:layout_alignLeft="@+id/button"

      android:layout_alignStart="@+id/button"

      android:layout_below="@+id/textView2" />

   <TextView

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:text="Paired devices:"

      android:id="@+id/textView2"

      android:textColor="#ff34ff06"

      android:textSize="25dp"

      android:layout_below="@+id/button4"

      android:layout_alignLeft="@+id/listView"

      android:layout_alignStart="@+id/listView" />

</RelativeLayout>

<resources>

   <string name="app_name">My Application</string>

   <string name="hello_world">Hello world!</string>

   <string name="action_settings">Settings</string>

</resources>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.example.sairamkrishna.myapplication" >
   <uses-permission android:name="android.permission.BLUETOOTH"/>
   <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
   
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:theme="@style/AppTheme" >
      
      <activity
         android:name=".MainActivity"
         android:label="@string/app_name" >
         
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
         
      </activity>
      
   </application>
</manifest>