String[] videoFileList = {
   "/sdcard/Video/Android 2.0 Official Video_low.mp4",
   "/sdcard/Video/Android 2.2 Official Video_low.mp4"
 };

# Thumbnails.MICRO_KIND[작은 이미지 사이즈], Thumbnails.MINI_KIND[중간 이미지 사이즈]
Bitmap bmThumbnail;
bmThumbnail = ThumbnailUtils.createVideoThumbnail(videoFileList[0], Thumbnails.MICRO_KIND);

ImageView imageThumbnail = (ImageView)row.findViewById(R.id.Thumbnail);
imageThumbnail.setImageBitmap(bmThumbnail);

public class CameraPreview extends Activity 
{
	@Override
	public void onCreate(Bundle savedInstanceState)
	{
	    
	    //전원버튼
            IntentFilter offfilter = new IntentFilter (Intent.ACTION_SCREEN_OFF);
            registerReceiver(screenoff, offfilter);
	}

        @Override
	public void onDestroy(){
		unregisterBroadcast();//전원버튼
	}

	//전원버튼
	private void unregisterBroadcast() {
		unregisterReceiver(screenoff);
	}
    
	BroadcastReceiver screenoff = new BroadcastReceiver(){
		public static final String Screenoff = "android.intent.action.SCREEN_OFF";
		
		@Override
		public void onReceive(Context context, Intent intent){
			if(!intent.getAction().equals(Screenoff))return;
    		
			// 여기에 전원 버튼을 눌렸을때 
			// 어떠한 일을 할건지 결정하면됩니다
    		}
	 };
}