This is how you can create gridview programmatically,
    GridView grid = new GridView(this);
    grid.setId(ViewIdentification.getId());
    grid.setLayoutParams(new GridView.LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT));
    grid.setBackgroundColor(Color.WHITE);
    grid.setNumColumns(3);
    grid.setColumnWidth(GridView.AUTO_FIT);
    grid.setVerticalSpacing(5);
    grid.setHorizontalSpacing(5);
    grid.setStretchMode(GridView.STRETCH_COLUMN_WIDTH);
Add the above view to your layout. And here you can get the height and width of the display.
DisplayMetrics displaymetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay()
            .getMetrics(displaymetrics);
int width = displaymetrics.widthPixels;
int height = displaymetrics.heightPixels;
And here is the adapter class :
public class ImageAdapter extends BaseAdapter {
    private Context mContext;
    private Bitmap[]mis_fotos;
    public ImageAdapter(Context c) {
        mContext = c;    }
    public int getCount() {
        return mis_fotos.length;
        }
    public Object getItem(int position) {
        return position;    }
    public long getItemId(int position) {
        return 0;    }
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView;
        if (convertView == null) {
            imageView = new ImageView(mContext);
            imageView.setLayoutParams(new GridView.LayoutParams(width/3, height/3));
            imageView.setScaleType(ImageView.setScaleType(ScaleType.FIT_XY));
            imageView.setPadding(0, 0, 0, 0);
        } else {
            imageView = (ImageView) convertView;
        }
        imageView.setImageBitmap(mis_fotos[position]);
        return imageView;
    }
}
Then, It's upto you, If you are passing dynamic URL, change your adapter accordingly.
set your adapter to your gridview. 
Let me know if you have any issues.