Can I use startActivity in onCreateViewHolder?

Question

I make a onClick in recyclerView onCreateViewHolder like this.

@Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.fragment_homeinfo, parent, false);
        final ViewHolder holder = new ViewHolder(itemView);

        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(v.getContext(), Integer.toString(holder.getAdapterPosition()), Toast.LENGTH_SHORT).show();
            }
        });
        return holder;
    }

and I want to put this code in onClick.

final String serverURL = "http://youngh.cafe24app.com/qrock/views/qrock_pk/user_email";

                myDb = new DatabaseHelper(v.getContext());  //is it Possible?
                final String token = myDb.getToken();
                final String email = myDb.getEmail();

                StringRequest stringRequest = new StringRequest(Request.Method.GET, serverURL,
                        new Response.Listener<String>() {
                            @Override
                            public void onResponse(String response) {
                                Intent myIntent = new Intent(v.getContext(), mainActivity.class);   //v.getContent() <- ERROR
                                startActivity(myIntent);
                                finish();

                                overridePendingTransition(R.xml.madefadein, R.xml.splashfadeout);
                            }
                        }, new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        switch(error.networkResponse.statusCode)
                        {

                        }
                    }
                }){
                    @Override
                    protected Map<String, String> getParams() throws AuthFailureError {
                        Map<String, String> params = new HashMap<String, String>();
                        //params.put("qrock_pk", qrockPk);
                        params.put("user_email", email);
                        return params;
                    }

                    @Override
                    public Map<String, String> getHeaders() throws AuthFailureError {
                        Map<String, String> headers = new HashMap<>();
                        headers.put("x-access-token", token);
                        return headers;
                    }
                };
                MySingleton.getInstance(v.getContext()).addToRequestQue(stringRequest);

But in onCreateViewHolder, I can't cast startActivity(), finish() etc. I want to make when I click a recyclerViewItem, start these code and move to another activity. How to use these code???

I'm sorry I can not speak English well.

You need to pass context to use startActivity(), finish(). so whenever you want to use startActivity() it is call like this context.startActivity(). Yes you can use this code on onClick() — Andy Developer, Sep 22 '17 at 06:12
Use context and cast and cast context to Activity like this:Activity activity = (Activity) context; — Vijay Chaudhary, Sep 22 '17 at 06:12
refer this link : https://stackoverflow.com/questions/28767413/how-to-open-a-different-activity-on-recyclerview-item-onclick — zephyr, Sep 22 '17 at 06:13
You could also make a callback to the activity that holds the adapter and launch from there. Or better yet trigger an event that the parent activity subscribes to and launch accordingly. — sam_c, Sep 22 '17 at 06:37

Suhayl SH · Accepted Answer · 2017-09-22T06:19:17.950

2

Try this:

In onCreateViewHolder:

context = v.getContext()

Then go on and use context.startActivity() and ((Activity)context).finish();

edited Sep 22 '17 at 06:19

answered Sep 22 '17 at 06:13

Suhayl SH

1,213
1
11
16

Can you try with ((Activity)context).finish(); – Suhayl SH Sep 22 '17 at 06:20
It works! but Can I declare `DatabaseHelper myDb;` in homeAdapter? and I want to use myDb like this `myDb = new DatabaseHelper(v.getContext()); ` Is it possible? – SunSpike Sep 22 '17 at 06:27

score 0 · Answer 2 · answered Sep 22 '17 at 06:14

0

Try this code

Intent myIntent= new Intent(v.getContext(), mainActivity.class);
myIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
v.getContext().startActivity(myIntent);
finish();

answered Sep 22 '17 at 06:14

Ramesh Yogu

135
7

score 0 · Answer 3 · answered Sep 22 '17 at 06:14

0

You can use like this;

Intent myIntent = new Intent(getApplicationContext(), mainActivity.class);
getApplicationContext().startActivity(myIntent);

answered Sep 22 '17 at 06:14

Vishal Vaishnav

3,346
3
26
57

starting an activity from application context would require specifics flags like FLAG_NEW_TASK – Re'em Dec 19 '18 at 08:47

Sharath kumar · Answer 4 · 2017-09-22T06:23:50.067

Instead of onCreateViewHolder do the click function onBindViewHolder. The reason is onBindViewHolder is called everytime add onCreateViewHolder is called only while creating views.

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

    holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //use holder.itemView.getContext() to get context
            Toast.makeText( holder.itemView.getContext().getContext(), Integer.toString(holder.getAdapterPosition()), Toast.LENGTH_SHORT).show();
        }
    });

score 0 · Answer 5 · answered Sep 22 '17 at 06:16

0

you can use like this ((Activity)ctx).startActivity();

answered Sep 22 '17 at 06:16

Vij

445
2
9

where ctx is context – Vij Sep 22 '17 at 06:16

score 0 · Answer 6 · answered Sep 22 '17 at 06:22

0

You just need to change getContext() to view.getContext();

 @Override
        public void onClick(View view) {
           view.getContext().startActivity(new Intent(view.getContext(), MainActivity.class));    
        }

answered Sep 22 '17 at 06:22

Ankita

1,129
1
8
15

score 0 · Answer 7 · answered Sep 22 '17 at 06:39

0

1. onCreateViewHolder

Here you have to do create/initialize your views

2. onBindViewHolder

Here you have to do logics, bind the views , on click actions

answered Sep 22 '17 at 06:39

Rajasekhar

2,345
1
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20

Can I use startActivity in onCreateViewHolder?

7 Answers7