Recycler view is not refreshed when i delete an item from recycler view?

Question

When I try to delete an item from recyclerview (Full Image Activity), I call onfinish() method to go back to previous activity i.e recyclerview(GalleryActivity).

But the image which I delete is still visible and when I exit the gallery Activity and enter again then it is refreshed.

Any Solution to it, so that it can refresh when the item is deleted.When i delete an image this thing appears

This is my Recyclerview Adapter

public class RecyclerViewAdapter extends RecyclerView.Adapter {

private ArrayList<String> yeniliste;
private Context context;

public RecyclerViewAdapter(Context context, ArrayList<String> itemList) {
    this.yeniliste = itemList;
    this.context = context;
}

@Override
public RecyclerViewHolders onCreateViewHolder(ViewGroup parent, int viewType) {
    View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.gallery_item, null);
    RecyclerViewHolders rcv = new RecyclerViewHolders(layoutView);
    return rcv;
}

@Override
public void onBindViewHolder(final RecyclerViewHolders holder, final int position) {
    Bitmap bitmap = BitmapFactory.decodeFile(yeniliste.get(position));
    holder.countryPhoto.setImageBitmap(bitmap);
    holder.countryPhoto.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(v.getContext(),GalleryFullImage.class);
            intent.putExtra("realid",String.valueOf(holder.getAdapterPosition()));
            v.getContext().startActivity(intent);
        }
    });
}

@Override
public int getItemCount() {
    return this.yeniliste.size();
}


public static class RecyclerViewHolders extends RecyclerView.ViewHolder implements View.OnClickListener{

    public ImageView countryPhoto;

    public RecyclerViewHolders(View itemView) {
        super(itemView);
        countryPhoto = (ImageView)itemView.findViewById(R.id.country_photo);
    }

    @Override
    public void onClick(View view) {
        Toast.makeText(view.getContext(), "Clicked Country Position = " + getAdapterPosition(), Toast.LENGTH_SHORT).show();

    }

}

public void removeItem(int position)
{
    yeniliste.remove(position);
    notifyItemRemoved(position);
    notifyItemRangeChanged(position, yeniliste.size());
}}

removeItem method is also not Working. This is my Full Image Activity. When I delete Image from here. It is not refreshing GalleryActivity.

public class GalleryFullImage extends AppCompatActivity {
String idPath;
String realid;
ArrayList<String> stringList;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.gallery_fullimage);

    stringList = new ArrayList<>();
    String targetPath= Environment.getExternalStorageDirectory().getAbsolutePath() + "/My Images/";
    File targetDirector = new File(targetPath);
    File[] files = targetDirector.listFiles();
    Arrays.sort( files, new Comparator()
    {
        public int compare(Object o1, Object o2) {

            if (((File)o1).lastModified() > ((File)o2).lastModified()) {
                return -1;
            } else if (((File)o1).lastModified() < ((File)o2).lastModified()) {
                return +1;
            } else {
                return 0;
            }
        }

    });
    for (File file : files){
        stringList.add(file.getAbsolutePath());
    }

    Intent i = getIntent();
    idPath = i.getStringExtra("realid");
    realid = stringList.get(Integer.parseInt(idPath));
    Log.d("wow",realid);
    File imgFile = new  File(realid);
    if(imgFile.exists()) {
        Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());
        ImageView myImage = (ImageView) findViewById(R.id.gallery_fullimg);
        myImage.setImageBitmap(myBitmap);
        myImage.setOnTouchListener(new ImageMatrixTouchHandler(getApplicationContext()));
    }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {

    getMenuInflater().inflate(R.menu.delete, menu);

    return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {

    final int id = item.getItemId();

    if (id == R.id.action_delete) {
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(GalleryFullImage.this);
        alertDialog.setTitle("Confirm Delete...");
        alertDialog.setMessage("Are you sure you want delete this?");
        alertDialog.setPositiveButton("YES", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int which) {
                RecyclerViewAdapter rcAdapter = new RecyclerViewAdapter(getApplicationContext(), stringList);
                rcAdapter.removeItem(Integer.parseInt(idPath));
                File file = new File(realid);
                boolean deleted = file.delete();
                Log.v("log_tag","deleted: " + deleted);
                Toast.makeText(GalleryFullImage.this,"File Deleted", Toast.LENGTH_SHORT).show();
                finish();
            }
        });
        alertDialog.setNegativeButton("NO", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                Toast.makeText(getApplicationContext(), "You clicked on NO", Toast.LENGTH_SHORT).show();
                dialog.cancel();
            }
        });
        alertDialog.show();
        return true;
    }
    return super.onOptionsItemSelected(item);
}}

This is GalleryActivity .

public class GalleryActivity extends AppCompatActivity {
ArrayList<String> stringList;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_gallery);
    setTitle("Gallery");
    stringList = new ArrayList<>();
    String targetPath= Environment.getExternalStorageDirectory().getAbsolutePath() + "/My Images/";
    File targetDirector = new File(targetPath);
    File[] files = targetDirector.listFiles();
    Arrays.sort( files, new Comparator()
    {
        public int compare(Object o1, Object o2) {

            if (((File)o1).lastModified() > ((File)o2).lastModified()) {
                return -1;
            } else if (((File)o1).lastModified() < ((File)o2).lastModified()) {
                return +1;
            } else {
                return 0;
            }
        }

    });
    for (File file : files){
        stringList.add(file.getAbsolutePath());
    }

    RecyclerView rView = (RecyclerView)findViewById(R.id.recycler_view);
    RecyclerView.LayoutManager layoutManager = new GridLayoutManager(getApplicationContext(),2);
    rView.setHasFixedSize(true);
    rView.setLayoutManager(layoutManager);
    RecyclerViewAdapter rcAdapter = new RecyclerViewAdapter(getApplicationContext(), stringList);
    rView.setAdapter(rcAdapter);


}
@Override
protected void onResume() {
    super.onResume();
}}

Answer 1

set your code in setImage() method like that call this method in onCreate and onResume :-

   public void setImage(){
   stringList.clear();
   String targetPath= 
    Environment.getExternalStorageDirectory().getAbsolutePath() + "/My Images/";
    File targetDirector = new File(targetPath);
    File[] files = targetDirector.listFiles();
Arrays.sort( files, new Comparator()
{
    public int compare(Object o1, Object o2) {

        if (((File)o1).lastModified() > ((File)o2).lastModified()) {
            return -1;
        } else if (((File)o1).lastModified() < ((File)o2).lastModified()) {
            return +1;
        } else {
            return 0;
        }
    }

});
for (File file : files){
    stringList.add(file.getAbsolutePath());
}

RecyclerView rView = (RecyclerView)findViewById(R.id.recycler_view);
RecyclerView.LayoutManager layoutManager = new GridLayoutManager(getApplicationContext(),2);
rView.setHasFixedSize(true);
rView.setLayoutManager(layoutManager);
RecyclerViewAdapter rcAdapter = new RecyclerViewAdapter(getApplicationContext(), stringList);
rView.setAdapter(rcAdapter);

}

Hope this is Helpful;

Answer 2

Do this in GalleryActivity

@Override
protected void onResume() {
    super.onResume();
    if(rView != null){
      yourAdapter.notifyDataSetChanged();
    }

 };

Make the rView and the adapter global variables.