display image from SD card or internal storage to view pager android

Question

have an activity which reads images from drawable folder and shows them in viewpager like slide show. below is my code for that. Now I want to show images from my SD card or internal storage in to viewpager. what changes should be made in below code to read images from SD card or internal storage and display them in viewpager like slide show.

Activity

    public class MainActivity extends AppCompatActivity {
    ViewPager viewPager;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        setContentView(R.layout.activity_main);

        viewPager = (ViewPager) findViewById(R.id.viewPager);

        ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(this);

        viewPager.setAdapter(viewPagerAdapter);
        Timer timer = new Timer();
        timer.scheduleAtFixedRate(new MyTimerTask(), 3000,3000);

    }
    public class MyTimerTask extends TimerTask {

        @Override
        public void run() {

            MainActivity.this.runOnUiThread(new Runnable() {
                @Override
                public void run() {

                    if (viewPager.getCurrentItem() == 0) {
                        viewPager.setCurrentItem(1);
                    } else if (viewPager.getCurrentItem() == 1) {
                        viewPager.setCurrentItem(2);
                    } else if (viewPager.getCurrentItem() == 2) {
                        viewPager.setCurrentItem(3);
                    } else if (viewPager.getCurrentItem() == 3) {
                        viewPager.setCurrentItem(4);
                    } else {
                            viewPager.setCurrentItem(0);
                        }

                    }


                ;

            });
        }
    }
}

ViewPagerAdapter

    public class ViewPagerAdapter extends PagerAdapter {

    private Context context;
    private LayoutInflater layoutInflater;
   private Integer [] images = {R.drawable.index1,R.drawable.index2,R.drawable.index3,R.drawable.index4,R.drawable.index5};

    public ViewPagerAdapter(Context context) {

        this.context = context;
    }
    @Override
    public int getCount() {

        return images.length;
    }
    @Override
    public boolean isViewFromObject(View view, Object object) {

        return view == object;
    }
    @Override
    public Object instantiateItem(ViewGroup container, final int position) {

        layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View view = layoutInflater.inflate(R.layout.custom_layout, null);
        ImageView imageView = (ImageView) view.findViewById(R.id.imageView);
        imageView.setImageResource(images[position]);


        ViewPager vp = (ViewPager) container;
        vp.addView(view, 0);
        return view;
    }
    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {

        ViewPager vp = (ViewPager) container;
        View view = (View) object;
        vp.removeView(view);

    }
}

Answer 1

You can use Picasso to load images from sdcard. Guide here:
Picasso Library

In your case:

    String baseDir = Environment.getExternalStorageDirectory().getAbsolutePath(); // retrieve the storage dir
    Picasso.with(context).load(new File(baseDir + File.separator + your_filename)).into(imageView);