Android學習筆記 - 錄音(MediaRecorder)

1. 要進行錄音需先取得錄音的權限，加上需將錄音檔寫到記憶卡，因此需在AndroidManifest.xml允許存取android.permission.RECORD_AUDIO及android.permission.WRITE_EXTERNAL_STORAGE這二個權限。

2.MediaRecorderExample.java

package tw.nicky;
import java.io.File;
import java.io.IOException;
import android.app.Activity;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.Button;

public class MediaRecorderExample extends Activity {
 private Button recordButn;
 private Button stopButn;
 private MediaRecorder mediaRecorder = null;

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  recordButn = (Button) findViewById(R.id.recordButn);
  stopButn = (Button) findViewById(R.id.stopButn);

  //錄音
  recordButn.setOnClickListener(new View.OnClickListener() {
   public void onClick(View v) {
    //設定錄音檔名
    String fileName = "record.amr";
    try {
     File SDCardpath = Environment.getExternalStorageDirectory();
                    File myDataPath = new File( SDCardpath.getAbsolutePath() + "/download" );
                    if( !myDataPath.exists() ) myDataPath.mkdirs();
     File recodeFile = new File(SDCardpath.getAbsolutePath() + "/download/"+fileName);
     
     mediaRecorder = new MediaRecorder();

     //設定音源
     mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
     //設定輸出檔案的格式
     mediaRecorder
       .setOutputFormat(MediaRecorder.OutputFormat.RAW_AMR);
     //設定編碼格式
     mediaRecorder
       .setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
     //設定錄音檔位置
     mediaRecorder
       .setOutputFile(recodeFile.getAbsolutePath());

     mediaRecorder.prepare();

     //開始錄音
     mediaRecorder.start();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
  });

  //停止錄音
  stopButn.setOnClickListener(new View.OnClickListener() {
   public void onClick(View v) {
    if(mediaRecorder != null) {
     mediaRecorder.stop();
     mediaRecorder.release();
     mediaRecorder = null;
    }
   }
  });

 }
}

3. main.xml(Layout)

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout
android:id="@+id/widget0"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
>
<Button
android:id="@+id/recordButn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="錄音"
android:layout_x="68px"
android:layout_y="44px"
>
</Button>
<Button
android:id="@+id/stopButn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="停止"
android:layout_x="170px"
android:layout_y="43px"
>
</Button>
</AbsoluteLayout>

4. AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="tw.nicky"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".MediaRecorderExample"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
    <uses-permission android:name="android.permission.RECORD_AUDIO"></uses-permission>
</manifest> 

5. 執行畫面