android view之imageswitcher

public class imageswitcher extends Activity implements
        AdapterView.OnItemSelectedListener, ViewSwitcher.ViewFactory {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        mSwitcher = (ImageSwitcher) findViewById(R.id.switcher);
        mSwitcher.setFactory(this);
        mSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_in));
        mSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_out));

        Gallery g = (Gallery) findViewById(R.id.gallery);
        g.setAdapter(new ImageAdapter(this));
        g.setOnItemSelectedListener(this);
    }
    
    public void onItemSelected(AdapterView parent, View v, 
                                int position, long id) {
        mSwitcher.setImageResource(mImageIds[position]);
    }

    public void onNothingSelected(AdapterView parent) {
    }
    
    public View makeView() {
        ImageView i = new ImageView(this);
        i.setScaleType(ImageView.ScaleType.FIT_CENTER);
        i.setLayoutParams(new ImageSwitcher.LayoutParams(
                LayoutParams.FILL_PARENT,
                LayoutParams.FILL_PARENT));
        return i;
    }

    private ImageSwitcher mSwitcher;

    public class ImageAdapter extends BaseAdapter {
        public ImageAdapter(Context c) {
            mContext = c;
        }

        public int getCount() {
            return mImageIds.length;
        }

        public Object getItem(int position) {
            return position;
        }

        public long getItemId(int position) {
            return position;
        }

        public View getView(int position, View convertView, 
                            ViewGroup parent) {
            ImageView i = new ImageView(mContext);

            i.setImageResource(mImageIds[position]);
            i.setAdjustViewBounds(true);
            i.setLayoutParams(new Gallery.LayoutParams(
                    LayoutParams.WRAP_CONTENT, 
                    LayoutParams.WRAP_CONTENT));
            return i;
        }

        private Context mContext;
    }

    private Integer[] mImageIds = {
            R.drawable.photo1, R.drawable.photo2, 
            R.drawable.photo3, R.drawable.photo4, 
            R.drawable.photo5, R.drawable.photo6,
            R.drawable.photo7, R.drawable.photo8};
}