Android開發 ---- 兩分鐘寫一個錄音演示軟件

Android開發 ---- 兩分鐘寫一個錄音演示軟件

    Android自帶的SoundRecoder軟件寫得很簡單，就3個Java文件，最有特色的還算哪個指針了。這裏並不是要介紹那個個指針的實現過程，其實也簡單，就是一個算法，通過錄音過程中獲取的振幅來實現指針的偏移。

<span style="font-size:16px;">MediaRecorder.getMaxAmplitude(); // 得到錄音時的最大振幅</span>

    趕緊上代碼吧，兩分鐘的時間馬上就過了...界面設計很簡單，3個按鈕（開始錄音，停止錄音，播放錄音）。

一、新建工程SoundRecoderDemo

二、main.xml（佈局文件）

<span style="font-size:16px;"><?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="horizontal" >

        <Button
            android:id="@+id/start"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="start" />

        <Button
            android:id="@+id/stop"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="stop" />

        <Button
            android:id="@+id/play"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="play" />

</LinearLayout></span>

三、SoundRecorderActivity（具體錄音實現）

<span style="font-size:16px;">import java.io.File;
import java.io.IOException;

import android.app.Activity;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class SoundRecorderActivity extends Activity implements OnClickListener {

    private Button btnStart;
    private Button btnStop;
    private Button btnPlay;

    private MediaRecorder mMediaRecorder;
    private File recAudioFile;
    private MusicPlayer mPlayer;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        setupViews();
    }

    private void setupViews() {
        btnStart = (Button) findViewById(R.id.start);
        btnStop = (Button) findViewById(R.id.stop);
        btnPlay = (Button) findViewById(R.id.play);

        btnStart.setOnClickListener(this);
        btnStop.setOnClickListener(this);
        btnPlay.setOnClickListener(this);

        recAudioFile = new File("/mnt/sdcard", "new.amr");
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.start:
            startRecorder();
            break;
        case R.id.stop:
            stopRecorder();
            break;
        case R.id.play:
            mPlayer = new MusicPlayer(SoundRecorderActivity.this);
            mPlayer.playMicFile(recAudioFile);
            break;
        default:
            break;
        }
    }

    private void startRecorder() {
        mMediaRecorder = new MediaRecorder();
        if (recAudioFile.exists()) {
            recAudioFile.delete();
        }

        mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);
        mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
        mMediaRecorder.setOutputFile(recAudioFile.getAbsolutePath());
        try {
            mMediaRecorder.prepare();
        } catch (IllegalStateException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        mMediaRecorder.start();
    }

    private void stopRecorder(){
        if (recAudioFile!=null) {
            mMediaRecorder.stop();
            mMediaRecorder.release();
        }
    }
}</span>

四、播放類（MusicPlayer）

<span style="font-size:16px;">import java.io.File;

import android.content.Context;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.net.Uri;
import android.util.Log;

public class MusicPlayer {
    private final static String TAG = "MusicPlayer";
    private static MediaPlayer mMediaPlayer;
    private Context mContext;

    public MusicPlayer(Context context){
        mContext = context;
    }

    public void playMicFile(File file){
        if (file!=null && file.exists()) {
            Uri uri = Uri.fromFile(file);
            mMediaPlayer = MediaPlayer.create(mContext, uri);
            mMediaPlayer.start();
            mMediaPlayer.setOnCompletionListener(new OnCompletionListener() {

                public void onCompletion(MediaPlayer mp) {
                    //TODO:finish
                    Log.i(TAG, "Finish");
                }
            });
        }
    }

    public void stopPlayer(){
        if(mMediaPlayer.isPlaying()){
            mMediaPlayer.stop();
            mMediaPlayer.release();
        }
    }
}
</span>

五、添加錄音權限

<span style="font-size:16px;"><uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /></span>

完成，運行查看效果。代碼很簡單，沒有註釋，感興趣的看API！！

Demo下載地址：http://download.csdn.net/detail/tangcheng_ok/3837435