GalleryAdapter adapter = new GalleryAdapter(this, mIds);mGallery.setAdapter(adapter);

public class GalleryAdapter extends BaseAdapter {  private Context mContext;  private int mImageHeight;  private int[] mIds;  public GalleryAdapter(Context context, int[] ids) {   this.mContext = context;   this.mIds = ids;   init();  }  private void init() {   mImageHeight = px2dip(mContext, getScreenHeight(MainActivity.this));  }  @Override  public int getCount() {   return mIds.length;  }  @Override  public Object getItem(int position) {   return position;  }  @Override  public long getItemId(int position) {   return position;  }  @Override  public View getView(int position, View convertView, ViewGroup parent) {   final ImageView imageView = new ImageView(mContext);   if (position < mIds.length) {    int imageId = mIds[position];    imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);//設置圖片居中    imageView.setLayoutParams(new Gallery.LayoutParams(      Gallery.LayoutParams.FILL_PARENT, mImageHeight));    Bitmap bitmap = readBitMap(mContext, imageId);//用節省內存的方式加載圖片，防止OOM    imageView.setImageBitmap(bitmap);    overridePendingTransition(R.anim.push_in, R.anim.push_out);//圖片切換動畫   }   return imageView;  }}

Timer timer = new Timer();timer.schedule(task, 3000, 3000);// 每3秒切換一張圖片private TimerTask task = new TimerTask() {  @Override  public void run() {   Message message = new Message();   message.what = 0;   index = mGallery.getSelectedItemPosition();   handler.sendMessage(message);   index++;   if (index == mIds.length - 1) {    this.cancel();    MainActivity.this.finish();    Intent intent = new Intent(MainActivity.this, Test.class);    startActivity(intent);   }  }};//不能直接在task中更新UI，所以用handler向主線程發送消息private Handler handler = new Handler() {  @Override  public void handleMessage(Message msg) {   super.handleMessage(msg);   switch (msg.what) {   case 0:    mGallery.setSelection(index);    break;   default:    break;   }  }};

public static Bitmap readBitMap(Context context, int resId) {  BitmapFactory.Options opt = new BitmapFactory.Options();  opt.inPreferredConfig = Bitmap.Config.RGB_565;  opt.inPurgeable = true;  opt.inInputShareable = true;  // 獲取資源圖片  InputStream is = context.getResources().openRawResource(resId);  return BitmapFactory.decodeStream(is, null, opt);}