Android 背景執行(Service)
大部分使用者在手機上看到的畫面都是前端的程式(Activity)，
如果是要在背景執行的程式，則需要寫成Service並繼承android.app.Service，
由於是在背景執行所以是要寫成Service而不是Activity，
因此需在AndroidManifest新增一個Service。

[code]
[Activity]

start=(Button)findViewById(R.id.start);
stop=(Button)findViewById(R.id.stop);

start.setOnClickListener(new OnClickListener(){

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Intent intent = new Intent(RecordingActivity.this, RecordingService.class);
startService(intent);
}});
stop.setOnClickListener(new OnClickListener(){

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(RecordingActivity.this, RecordingService.class);
stopService(intent);
}});
[/code]

[code]
[Service]

public class RecordingService extends Service {
private MediaRecorder mediaRecorder = null;

@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}

@Override
public void onStart(Intent intent,int startId)
{

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();
}
super.onStart(intent, startId);
}

@Override
public void onDestroy() {
if(mediaRecorder != null) {
mediaRecorder.stop();
mediaRecorder.release();
mediaRecorder = null;
}
super.onDestroy();
}


}
[/code]

要記得加入權限喔。

可以參考：http://hastdio.blogspot.com/HA程式設計

感謝~!