电话监听器案例

(1)先定义一个服务 服务用来监听电话状态 开启服务

(2)在服务的oncreate方法里面实例化TelephoneManager类的实例

(3)注册一个电话监听

(4)定义一个电话监听的类

(5) 实现录音的功能

public class PhoneService extends Service {

    private MediaRecorder recorder;
    @Override
    public IBinder onBind(Intent intent) {

        return null;
    }

    //服务第一次被开启的时候调用
    @Override
    public void onCreate() {

        //[1]获取电话管理者的实例
        TelephonyManager tm  = (TelephonyManager) getSystemService(TELEPHONY_SERVICE);

        //[2]注册一个电话状态的监听
        tm.listen(new MyPhoneStateListenrer(), PhoneStateListener.LISTEN_CALL_STATE);

        super.onCreate();
    }

    //监听电话的状态
    private class MyPhoneStateListenrer extends PhoneStateListener{
        //当设备的状态发生改变的时候调用

        @Override
        public void onCallStateChanged(int state, String incomingNumber) {

            //[3]具体判断一下  电话是处于什么状态
            switch (state) {
            case TelephonyManager.CALL_STATE_IDLE:  //空闲状态
                if (recorder!=null) {
                     recorder.stop();  //停止录
                     recorder.reset();   // You can reuse the object by going back to setAudioSource() step
                     recorder.release(); // Now the object cannot be reused

                }

                break;

            case TelephonyManager.CALL_STATE_OFFHOOK://接听状态 

                System.out.println("开始录");
                //开启录
                 recorder.start();   // Recording is now started

                break;

            case TelephonyManager.CALL_STATE_RINGING:  //响铃状态

                System.out.println("我准备一个录音机出来 ");

                //[1]获取MediaRecorder类的实例
                recorder = new MediaRecorder();
                //[2]设置音频的来源
                 recorder.setAudioSource(MediaRecorder.AudioSource.MIC); //zet
                 //[3]设置音频的输出格式
                 recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
                 //[4]设置音频的编码方式
                 recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
                 //[5]保存的文件路径
                 recorder.setOutputFile("/mnt/sdcard/luyin.3gp");
                 //[5]准备录音
                 try {
                    recorder.prepare();
                } catch (IllegalStateException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }

                break;
            }

            super.onCallStateChanged(state, incomingNumber);
        }

    }

    //当服务销毁的时候执行
    @Override
    public void onDestroy() {
        super.onDestroy();
    }

}

(6)记得加上相应的权限

　　<uses-permission android:name="android.permission.READ_PHONE_STATE"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.RECORD_AUDIO" />
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>