public class MainActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public void onResume()
    {
        super.onResume();
        setContentView(createImageView("/sdcard/program-image.jpg"));
    }

    @Override
    public void onPause()
    {
        setContentView(createImageView("/sdcard/task-manager-image.jpg"));
        super.onPause();
    }

    private ImageView createImageView(String pathFile)
    {
        ImageView imageView = new ImageView(getApplication());
        imageView.setImageBitmap(BitmapFactory.decodeFile(pathFile));
        imageView.invalidate();
        return imageView;
    }
}