问显示SD卡中的图像列表

EN

 //---the images to display---     Integer[] imageIDs = {             R.drawable.a\_1,             R.drawable.a\_2,             R.drawable.a\_3,             R.drawable.a\_4,             R.drawable.a\_5,             R.drawable.a\_6,             R.drawable.a\_7

 };

@Override    
public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.selectimages);

    ListView listview = (ListView) findViewById(R.id.listview);
    listview.setAdapter(new ImageAdapter(this));

    listview.setOnItemClickListener(new OnItemClickListener() 
    {
        public void onItemClick(AdapterView parent, 
        View v, int position, long id) 
        {                
            Toast.makeText(getBaseContext(), 
                    "pic" + (position + 1) + " selected", 
                    Toast.LENGTH_SHORT).show();
        }
    });        
}

public class ImageAdapter extends BaseAdapter 
{
    private Context context;

    public ImageAdapter(Context c) 
    {
        context = c;
    }

    //---returns the number of images---
    public int getCount() {
        return imageIDs.length;
    }

    //---returns the ID of an item--- 
    public Object getItem(int position) {
        return position;
    }

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

    //---returns an ImageView view---
    public View getView(int position, View convertView, ViewGroup parent) 
    {
        ImageView imageView;
        if (convertView == null) {
            imageView = new ImageView(context);
            imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            imageView.setPadding(5, 5, 5, 5);
        } else {
            imageView = (ImageView) convertView;
        }
        imageView.setImageResource(imageIDs[position]);
        return imageView;
    }
}