package com.example.HelloGridView;

import android.app.Activity;
import android.os.Bundle;

public class HelloGridView extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    GridView gridview = (GridView) findViewById(R.id.gridview);
    gridview.setAdapter(new ImageAdapter(this));

    gridview.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
            Toast.makeText(HelloGridView.this, "" + position, Toast.LENGTH_SHORT).show();
        }
    });
    }

package com.example.HelloGridView;

public class ImageAdapter extends BaseAdapter {
private Context mContext;

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

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

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

public long getItemId(int position) {
return 0;
}

// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {  // if it's not recycled, initialize some attributes
    imageView = new ImageView(mContext);
    imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
    imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
    imageView.setPadding(8, 8, 8, 8);
} else {
    imageView = (ImageView) convertView;
}

imageView.setImageResource(mThumbIds[position]);
return imageView;
}

// references to our images
private Integer[] mThumbIds = {
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7,
R.drawable.sample_0, R.drawable.sample_1,
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7,
R.drawable.sample_0, R.drawable.sample_1,
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7
};

public class ChannelImageAdapter extends BaseAdapter {

    int mGalleryItemBackground;
    private Context mContext;
    File[] images;
    File[] files;
    public ChannelImageAdapter(Context c, int folderID) {
        mContext = c;

        File dir = new File(Environment.getExternalStorageDirectory() + "/images");
        files = dir.listFiles();
        images = files[folderID].listFiles();

    }
    public int getCount() {
        return images.length;
    }
    public Object getItem(int position) {
        return images[position].getAbsolutePath();
    }
    public long getItemId(int position) {
        return position;
    }
    public String getAlbumName(int folderID) {
        return files[folderID].getName();
    }
    public View getView(int position, View convertView, ViewGroup parent) {

        ImageView imageView;
        //Bitmap bm = BitmapFactory
        //      .decodeFile(images[position].getAbsolutePath());
        if (convertView == null) {
            imageView = new ImageView(mContext);
            imageView.setLayoutParams(new GridView.LayoutParams(100, 100));
            imageView.setScaleType(ImageView.ScaleType.FIT_XY);
            imageView.setPadding(5, 10, 5, 10);
        } else {
            imageView = (ImageView) convertView;
        }
        imageView.setImageBitmap(Bitmap.decode(images[position].getAbsoluteFile()));
        return imageView;

    }


}

int mGalleryItemBackground;
private Context mContext;
File[] images;
File[] files;
public ChannelImageAdapter(Context c, int folderID) {
    mContext = c;

    File dir = new File(Environment.getExternalStorageDirectory() + "/images");
    files = dir.listFiles();
    images = files[folderID].listFiles();

}
public int getCount() {
    return images.length;
}
public Object getItem(int position) {
    return images[position].getAbsolutePath();
}
public long getItemId(int position) {
    return position;
}
public String getAlbumName(int folderID) {
    return files[folderID].getName();
}
public View getView(int position, View convertView, ViewGroup parent) {

    ImageView imageView;

    if (convertView == null) {
        imageView = new ImageView(mContext);
        imageView.setLayoutParams(new GridView.LayoutParams(100, 100));
        imageView.setScaleType(ImageView.ScaleType.FIT_XY);
        imageView.setPadding(5, 10, 5, 10);
    } else {
        imageView = (ImageView) convertView;
    }
    imageView.setImageBitmap(Bitmap.decode(images[position].getAbsoluteFile()));
    return imageView;

}