public class TelReceiver extends BroadcastReceiver {
 public TelReceiver() {
 }

 @Override
 public void onReceive(Context context, Intent intent) {
 Intent i=new Intent(context,ListenPhoneService.class);
 i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 i.setAction(intent.getAction());
 i.putExtra(TelephonyManager.EXTRA_INCOMING_NUMBER,
  intent.getStringExtra(TelephonyManager.EXTRA_INCOMING_NUMBER));//電話號碼
 i.putExtra(TelephonyManager.EXTRA_STATE,
  intent.getStringExtra(TelephonyManager.EXTRA_STATE));//電話狀態(tài)
 context.startService(i);//啟動服務
 }
}

<receiver android:name=".TelReceiver" >
 <intent-filter android:priority="1000" >
 <action android:name="android.intent.action.PHONE_STATE" />
 <action android:name="android.intent.action.NEW_OUTGOING_CALL" />
 </intent-filter>
</receiver>

public class ListenPhoneService extends Service {
 private AudioManager mAudioManager;
 private TelephonyManager tm;
 public ListenPhoneService() {
 }
 @Override
 public void onCreate() {
 super.onCreate();
 mAudioManager=(AudioManager)getSystemService(Context.AUDIO_SERVICE);
 tm=(TelephonyManager)getSystemService(Service.TELEPHONY_SERVICE);
 }
 @Override
 public int onStartCommand(Intent intent, int flags, int startId) {
 if(intent.getAction().equals(Intent.ACTION_NEW_OUTGOING_CALL)){//去電廣播，android沒有來電話廣播
 }else{//去掉撥打電話就是來電狀態(tài)了
 //方法1
//獲得來電電話
// String number=intent.getStringExtra(TelephonyManager.EXTRA_INCOMING_NUMBER);
//獲得電話狀態(tài)
// String state=intent.getStringExtra(TelephonyManager.EXTRA_STATE);
//  Log.d("jereh", "incoming phone:" + number);
//  Log.d("jereh","call state:"+state);
//  TelephonyManager.EXTRA_STATE_IDLE: 沒有來電 或者 掛斷
//  TelephonyManagerEXTRA_STATE_OFFHOOK: 接起電話
//  TelephonyManager.EXTRA_STATE_RINGING:當電話呼入時,響鈴時
//  if(state.equals(TelephonyManager.EXTRA_STATE_RINGING)){
//  if(number.equals("13280998858")){//攔截指定的電話號碼
//  mAudioManager.setRingerMode(AudioManager.RINGER_MODE_SILENT);
//  Log.d("jereh","電話被攔截");
//  stopCall();
//   mAudioManager.setRingerMode(AudioManager.RINGER_MODE_NORMAL);//恢復鈴聲
//  }
//  }else if(state.equals(TelephonyManager.EXTRA_STATE_OFFHOOK)){
 //接起電話
//  recordCall();//開始錄音
//  }else if(state.equals(TelephonyManager.EXTRA_STATE_IDLE)){
//  stopCall();//停止錄音
//  }
 //方法2
  // 設置一個監(jiān)聽器,監(jiān)聽電話狀態(tài)
  tm.listen(listener,PhoneStateListener.LISTEN_CALL_STATE);
 }
 return super.onStartCommand(intent, flags, startId);
 }
 /**
 * 掛斷電話
 */
 private void stopCall(){
 try {
  //Android的設計將ServiceManager隱藏了，所以只能使用反射機制獲得。
  Method method=Class.forName("android.os.ServiceManager").getMethod("getService", String.class);
  IBinder binder=(IBinder)method.invoke(null, new Object[]{"phone"});//獲得系統(tǒng)電話服務
  ITelephony telephoney=ITelephony.Stub.asInterface(binder);
  telephoney.endCall();//掛斷電話
  stopSelf();//停止服務
 } catch (Exception e) {
  e.printStackTrace();
 }
 }
 PhoneStateListener listener=new PhoneStateListener(){
 @Override
 public void onCallStateChanged(int state,String incomingNumber){
  switch (state){
  //手機空閑了
  case TelephonyManager.CALL_STATE_IDLE:
   stopCall();//停止錄音
   break;
  //接起電話
  case TelephonyManager.CALL_STATE_OFFHOOK:
   recordCall();//開始錄音
   break;
  // 響鈴時
  case TelephonyManager.CALL_STATE_RINGING:
   Log.e("jereh", "來電號碼是："+ incomingNumber);
   // 如果該號碼屬于黑名單
   if (incomingNumber.equals("123456")) {
   // 如果是黑名單，就進行屏蔽
   stopCall();
   }
   break;
  }
 }
 };
 /**
 * 停止錄音
 */
 private void stopRecord(){
 if(recording){
  recorder.stop();
  recorder.release();
  recording=false;
  stopSelf();//停止服務
 }
 }
 /**
 * 電話錄音
 */
 private MediaRecorder recorder;
 private boolean recording ;
 private void recordCall(){
 Log.d("jereh", "record calling")
 if( Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
 recorder=new MediaRecorder();
 recorder.setAudioSource(MediaRecorder.AudioSource.MIC);//讀麥克風的聲音
 recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);//設置輸出格式
 recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);// 編碼方式
 File file=new File(Environment.getDownloadCacheDirectory().getAbsolutePath(),"recorder");
 if(!file.exists()){
  file.mkdir();
 }
 recorder.setOutputFile(file.getAbsolutePath() + "/"
 + System.currentTimeMillis() + "3gp");// 存放的位置是放在sd卡recorder目錄下
 try {
  recorder.prepare();
  recorder.start();
  recording=true;
 } catch (IOException e) {
  e.printStackTrace();
 }
 }
 }
 @Override
 public IBinder onBind(Intent intent) {
  throw new UnsupportedOperationException("Not yet implemented");
 }
}

<service
 android:name=".ListenPhoneService"
 android:enabled="true"
 android:exported="true" >
</service>