Cannot resolve method 'show(android.support.v4.app.FragmentTransaction, java.lang.String)'

Question

I am trying to create an image gallery with view pager. But I am getting an error saying Cannot resolve method 'show(android.support.v4.app.FragmentTransaction, java.lang.String)' for newFragment.show(ft, "slideshow");I have read similar questions related to Fragment Manager but they are not helping much as I am a newbie and I am using FragmentTransaction not FragmentManager. Can anyone help me to fix it ?

import android.app.Fragment;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;

import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    private String TAG = MainActivity.class.getSimpleName();
    private static final String endpoint = "http://demos.vetbossel.in/ajson/image.json";
    private ArrayList<Image1> images;
    private ProgressDialog pDialog;
    private GalleryAdapter mAdapter;
    private RecyclerView recyclerView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);

        pDialog = new ProgressDialog(this);
        images = new ArrayList<>();
        mAdapter = new GalleryAdapter(getApplicationContext(), images);

        RecyclerView.LayoutManager mLayoutManager = new GridLayoutManager(getApplicationContext(), 2);
        recyclerView.setLayoutManager(mLayoutManager);
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setAdapter(mAdapter);

        recyclerView.addOnItemTouchListener(new GalleryAdapter.RecyclerTouchListener(getApplicationContext(), recyclerView, new GalleryAdapter.ClickListener() {
            @Override
            public void onClick(View view, int position) {
                Bundle bundle = new Bundle();
                bundle.putSerializable("images", images);
                bundle.putInt("position", position);

                FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
                SlideshowDialogFragment newFragment = SlideshowDialogFragment.newInstance();
                newFragment.setArguments(bundle);
                newFragment.show(ft,"tag");
            }

            @Override
            public void onLongClick(View view, int position) {

            }
        }));

        fetchImages();
    }

    private void fetchImages() {

        pDialog.setMessage("Loading Images...");
        pDialog.show();

        JsonArrayRequest req = new JsonArrayRequest(endpoint,
                new Response.Listener<JSONArray>() {
                    @Override
                    public void onResponse(JSONArray response) {
                        Log.d(TAG, response.toString());
                        pDialog.hide();

                        images.clear();
                        for (int i = 0; i < response.length(); i++) {
                            try {
                                JSONObject object = response.getJSONObject(i);
                                Image1 image = new Image1();


                                JSONObject url = object.getJSONObject("url");
                                image.setSmall(url.getString("small"));
                                image.setMedium(url.getString("medium"));
                                image.setLarge(url.getString("large"));


                                images.add(image);

                            } catch (JSONException e) {
                                Log.e(TAG, "Json parsing error: " + e.getMessage());
                            }
                        }

                        mAdapter.notifyDataSetChanged();
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e(TAG, "Error: " + error.getMessage());
                pDialog.hide();
            }
        });

        // Adding request to request queue
        AppController.getInstance().addToRequestQueue(req);
    }
}

Answer 1

Actually Problem is in your SlideshowDialogFragment class. In Android there are two DialogFragment

1. android.support.v4.app.DialogFragment
2. android.app.DialogFragment

as your SlideshowDialogFragment class extend 2nd one, you cant use android.support.v4.app.FragmentTransaction.

Solution is go to SlideshowDialogFragment class and replace import android.app.DialogFragment; by import android.support.v4.app.DialogFragment;. Now everything will work fine.