前言

　　本章内容为Android开发者指南的 Framework Topics/Multimedia and Camera/Audio Capture章节，版本为Android 4.0 r1，翻译来自："呆呆大虾"，欢迎访问他的微博："http://weibo.com/popapa"，再次感谢"呆呆大虾" ！期待你一起参与翻译Android的相关资料，联系我over140@gmail.com。

注意: Android仿真器是不能捕获音频的，但实际的设备是有可能提供这个功能的。

/*

* 本程序需要读取外部存储的权限

* 如果输出文件写入外部存储，那就还需要写入权限来录音。

* 这些权限必须在AndroidManifest.xml文件中设置，类似如下

* <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

* <uses-permission android:name="android.permission.RECORD_AUDIO" />

*

*/

package com.android.audiorecordtest;

import android.app.Activity;

import android.widget.LinearLayout;

import android.os.Bundle;

import android.os.Environment;

import android.view.ViewGroup;

import android.widget.Button;

import android.view.View;

import android.view.View.OnClickListener;

import android.content.Context;

import android.util.Log;

import android.media.MediaRecorder;

import android.media.MediaPlayer;

import java.io.IOException;

public class AudioRecordTest extends Activity

{

private static final String LOG_TAG = "AudioRecordTest";

private static String mFileName = null;

private RecordButton mRecordButton = null;

private MediaRecorder mRecorder = null;

private PlayButton   mPlayButton = null;

private MediaPlayer   mPlayer = null;

private void onRecord(boolean start) {

if (start) {

startRecording();

} else {

stopRecording();

}

}

private void onPlay(boolean start) {

if (start) {

startPlaying();

} else {

stopPlaying();

}

}

private void startPlaying() {

mPlayer = new MediaPlayer();

try {

mPlayer.setDataSource(mFileName);

mPlayer.prepare();

mPlayer.start();

} catch (IOException e) {

Log.e(LOG_TAG, "prepare() 失败");

}

}

private void stopPlaying() {

mPlayer.release();

mPlayer = null;

}

private void startRecording() {

mRecorder = new MediaRecorder();

mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);

mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);

mRecorder.setOutputFile(mFileName);

mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);

try {

mRecorder.prepare();

} catch (IOException e) {

Log.e(LOG_TAG, "prepare()失败");

}

mRecorder.start();

}

private void stopRecording() {

mRecorder.stop();

mRecorder.release();

mRecorder = null;

}

class RecordButton extends Button {

boolean mStartRecording = true;

OnClickListener clicker = new OnClickListener() {

public void onClick(View v) {

onRecord(mStartRecording);

if (mStartRecording) {

setText("Stop recording");

} else {

setText("Start recording");

}

mStartRecording = !mStartRecording;

}

};

public RecordButton(Context ctx) {

super(ctx);

setText("Start recording");

setOnClickListener(clicker);

}

}

class PlayButton extends Button {

boolean mStartPlaying = true;

OnClickListener clicker = new OnClickListener() {

public void onClick(View v) {

onPlay(mStartPlaying);

if (mStartPlaying) {

setText("Stop playing");

} else {

setText("Start playing");

}

mStartPlaying = !mStartPlaying;

}

};

public PlayButton(Context ctx) {

super(ctx);

setText("Start playing");

setOnClickListener(clicker);

}

}

public AudioRecordTest() {

mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();

mFileName += "/audiorecordtest.3gp";

}

@Override

public void onCreate(Bundle icicle) {

super.onCreate(icicle);

LinearLayout ll = new LinearLayout(this);

mRecordButton = new RecordButton(this);

ll.addView(mRecordButton,

new LinearLayout.LayoutParams(

ViewGroup.LayoutParams.WRAP_CONTENT,

ViewGroup.LayoutParams.WRAP_CONTENT,

0));

mPlayButton = new PlayButton(this);

ll.addView(mPlayButton,

new LinearLayout.LayoutParams(

ViewGroup.LayoutParams.WRAP_CONTENT,

ViewGroup.LayoutParams.WRAP_CONTENT,

0));

setContentView(ll);

}

@Override

public void onPause() {

super.onPause();

if (mRecorder != null) {

mRecorder.release();

mRecorder = null;

}

if (mPlayer != null) {

mPlayer.release();

mPlayer = null;

}

}

}