在 RecyclerView 的新活动中打开项目（来自 json 的数据）

Question

Hello i'm new to android studio and i have code which is showing recycler view list from json data. Now i want to open items in new activity.I want to open item from recyclerview and show image and some text in new activity. I need solution code.

I have tried some ways but it doesn't work.

This is my code:

public class MainActivity extends AppCompatActivity {

public static final int CONNECTION_TIMEOUT = 10000;
public static final int READ_TIMEOUT = 15000;
private RecyclerView mRVFishPrice;
private AdapterFish mAdapter;
SwipeRefreshLayout mSwipeRefreshLayout;

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

    mSwipeRefreshLayout = (SwipeRefreshLayout)findViewById(R.id.swifeRefresh);
    mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
        @Override
        public void onRefresh() {
            new AsyncFetch().execute();
        }
    });
    new AsyncFetch().execute();
}

private class AsyncFetch extends AsyncTask<String, String, String> {
    ProgressDialog pdLoading = new ProgressDialog(MainActivity.this);
    HttpURLConnection conn;
    URL url = null;

    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        //this method will be running on UI thread
        pdLoading.setMessage("\tLoading...");
        pdLoading.setCancelable(false);
        pdLoading.show();

    }

    @Override
    protected String doInBackground(String... params) {
        try {


            url = new URL("https://MYURL.com");

        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return e.toString();
        }
        try {

            // Setup HttpURLConnection class to send and receive data from php and mysql
            conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(READ_TIMEOUT);
            conn.setConnectTimeout(CONNECTION_TIMEOUT);
            conn.setRequestMethod("GET");

            // setDoOutput to true as we recieve data from json file
            conn.setDoOutput(true);

        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
            return e1.toString();
        }

        try {

            int response_code = conn.getResponseCode();

            // Check if successful connection made
            if (response_code == HttpURLConnection.HTTP_OK) {

                // Read data sent from server
                InputStream input = conn.getInputStream();
                BufferedReader reader = new BufferedReader(new InputStreamReader(input));
                StringBuilder result = new StringBuilder();
                String line;

                while ((line = reader.readLine()) != null) {
                    result.append(line);
                }

                // Pass data to onPostExecute method
                return (result.toString());

            } else {

                return ("unsuccessful");
            }

        } catch (IOException e) {
            e.printStackTrace();
            return e.toString();
        } finally {
            conn.disconnect();
        }


    }

    @Override
    protected void onPostExecute(String result) {

        //this method will be running on UI thread
        mSwipeRefreshLayout.setRefreshing(false);


        pdLoading.dismiss();
        List<DataFish> data=new ArrayList<>();

        pdLoading.dismiss();
        try {

            JSONArray jArray = new JSONArray(result);

            for(int i=0;i<jArray.length();i++){
                JSONObject json_data = jArray.getJSONObject(i);
                DataFish fishData = new DataFish();
                fishData.fishImage= json_data.getString("fish_img");
                fishData.fishName= json_data.getString("fish_name");
                fishData.catName= json_data.getString("cat_name");
                fishData.sizeName= json_data.getString("size_name");
                fishData.price= json_data.getInt("price");
                data.add(fishData);
            }

            mRVFishPrice = (RecyclerView)findViewById(R.id.fishPriceList);
            mAdapter = new AdapterFish(MainActivity.this, data);
            mRVFishPrice.setAdapter(mAdapter);
            mRVFishPrice.setLayoutManager(new LinearLayoutManager(MainActivity.this));

        } catch (JSONException e) {
            Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_LONG).show();
        }

    }

}

}

I expect to open item from recyclerview list in new activity and show image item and some text.

Answer 1

You can archive this by passing an instance of the interface in your adapter class and implement that interface in your activity.

refer this to get insights link

Sample Snippets

Declare interface:

public interface AdapterCallback {
   void onFishClick(DataFish item);
}

Pass interface instance via setup your adapter in activity.

new AdapterFish(MainActivity.this, data, new AdapterCallback() {
    @Override
    void onfishClick(DataFish item) {
     // herer do your work
    }
});

In your adapter constructor

private AdapterCallback callback;
AdapterFish(Context contex, data, AdapterCallback callback) {
   ...
   this.callback = callback;
}

define click listener in a holder and inside a method call callback.onFishCall(selectedItem);

   OnBindViewHolder(...) {
       holder.button.onClicklistener(new OnClickListener{
          ...
          if(callback != null) { // for null check
              callback.onFishClikc(item);
          }
       });
   }