android - ギャラリーからのポップアップ画像 onItemClick

Question

私はアンドロイドが初めてです。ギャラリービューから選択した画像をポップアップする方法。コードを添付しました。

public class mygallerycode extends Activity
{
    Integer[] a={R.drawable.hotel1,R.drawable.hotel2,R.drawable.hotel3};

    Gallery gallery;
    ImageView imageview;

    public void onCreate(Bundle bb) {
        super.onCreate(bb);
        setContentView(R.layout.mygallery);
        gallery=(Gallery)findViewById(R.id.gallery1);
        gallery.setAdapter(new ImageAdapter(this));

        imageview=(ImageView)findViewById(R.id.imageView1);

        gallery.setOnItemClickListener(new OnItemClickListener()
        {
        public void onItemClick(AdapterView<?> parent, View v,
        int position, long id)
        {
        Toast.makeText(getBaseContext(),"picture" + (position+1) +"selected",Toast.LENGTH_SHORT).show();
        //imageview.setImageResource(a[position]);


        }
        });
    }
        class ImageAdapter extends BaseAdapter
        {

            private Context context;
            private int itemBackground;

            public ImageAdapter(Context c)
            {
                context = c;
                //---setting the style---
                TypedArray ta = obtainStyledAttributes(R.styleable.gallery1);
                itemBackground = ta.getResourceId(
                R.styleable.gallery1_android_galleryItemBackground, 1);
                ta.recycle();

            }

            @Override
            public int getCount() {
                // TODO Auto-generated method stub
                return a.length;
            }

            @Override
            public Object getItem(int position) {
                // TODO Auto-generated method stub
                return position;
            }

            @Override
            public long getItemId(int position) {
                // TODO Auto-generated method stub
                return position;
            }

            @Override
            public View getView(int position, View convertView,
                    ViewGroup parent) {
                // TODO Auto-generated method stub
                ImageView imageView = new ImageView(context);
                imageView.setImageResource(a[position]);
                imageView.setScaleType(ImageView.ScaleType.FIT_XY);
                imageView.setLayoutParams(new Gallery.LayoutParams(150, 120));
                imageView.setBackgroundResource(itemBackground);
                return imageView;
            }

        }
    }