Android實現電話錄音

在清單文件AndroidManifest.xml中添加權限：
    <uses-permission android:name="android.permission.READ_PHONE_STATE"/>
    <!-- 在SDCard中創建與刪除文件權限 -->
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
    <!-- 往SDCard寫入數據權限 -->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.RECORD_AUDIO"/>
    <!-- 訪問internet權限 -->
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>

public class PhoneListenerService extends Service {
@Override
public void onCreate() {
        TelephonyManager manager = 
                  (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
        //監聽電話的狀態
    manager.listen(new MyListener(), PhoneStateListener.LISTEN_CALL_STATE);
}

private final class MyListener extends PhoneStateListener {
    private String num;
    private MediaRecorder recorder;
    public void onCallStateChanged(int state, String incomingNumber) {
        switch (state) {
            case TelephonyManager.CALL_STATE_RINGING:  / 電話進來時 /
                num = incomingNumber;
                break;
            case TelephonyManager.CALL_STATEOFFHOOK: / 接起電話時 /
                try {
                    File file = new File(Environment.getExternalStorageDirectory(), num + "" + System.currentTimeMillis() + ".3gp");
                    recorder = new MediaRecorder();
                    recorder.setAudioSource(AudioSource.MIC);//聲音采集來源(話筒)
                    recorder.setOutputFormat(OutputFormat.THREE_GPP);//輸出的格式
                    recorder.setAudioEncoder(AudioEncoder.AMR_NB);//音頻編碼方式
                    recorder.setOutputFile(file.getAbsolutePath());//輸出方向
                    recorder.prepare();
                    recorder.start();
                } catch (Exception e) {
                    e.printStackTrace();
                }
                break;
            case TelephonyManager.CALL_STATE_IDLE:  / 無任何狀態時 /
                if (recorder != null) {
                    recorder.stop();
                    recorder.release();
                }
                break;
        }
    }
}
}</pre>