适配器乘以相同的数据android

Question

我有一个包含4个项目的SwitchTabActivty。就我而言，我使用第二项来通过回收站视图从Web获取一些数据。问题是，当我按下第四个项目（它包含一个开始活动的按钮）并返回到我的第二个标签时，我的再循环视图再次与相同的数据相乘。

Switchtabactivity：

public class SwitchTabActivity extends AppCompatActivity {


private SectionsPagerAdapter mSectionsPagerAdapter;

private ViewPager mViewPager;
private boolean pressToExit = false;


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

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    // Create the adapter that will return a fragment for each of the three
    // primary sections of the activity.
    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.container);
    mViewPager.setAdapter(mSectionsPagerAdapter);

    TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
    tabLayout.setupWithViewPager(mViewPager);
    tabLayout.getTabAt(0).setIcon(R.drawable.weather_tab);
    tabLayout.getTabAt(1).setIcon(R.drawable.events);
    tabLayout.getTabAt(2).setIcon(R.drawable.details_tab);
    tabLayout.getTabAt(3).setIcon(R.drawable.settings_tab);

    setColorTab(tabLayout);


}

private void setColorTab(TabLayout tab) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        tab.setTabTextColors(getResources().getColorStateList(R.color.tab_colors, null));
    } else {
        tab.setTabTextColors(getResources().getColorStateList(R.color.tab_colors));
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
}

@Override
public void onBackPressed() {
    if (!pressToExit) {
        Toast.makeText(this, "Press back again to exit.", Toast.LENGTH_SHORT).show();
        pressToExit = true;
    } else {

        Intent intent = new Intent(Intent.ACTION_MAIN);
        intent.addCategory(Intent.CATEGORY_HOME);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(intent);


    }
}

@Override
public void onResume() {
    super.onResume();
    pressToExit = false;
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_switch_tab, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}


public class SectionsPagerAdapter extends FragmentPagerAdapter {

    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        switch (position) {
            case 0:
                return WeatherFragment.newInstance(position);
            case 1:
                return EventFragment.newInstance(position);
            case 2:
                return OwnEventFragment.newInstance(position);
            case 3:
                return SettingsFragment.newInstance(position);
        }
        return null;

    }

    @Override
    public int getCount() {
        return 4;
    }


    @Override
    public CharSequence getPageTitle(int position) {
        switch (position) {
            case 0:
                return "Weather";
            case 1:
                return "Events";
            case 2:
                return "My Events";
            case 3:
                return "Settings";
        }
        return null;
    }

}

EventFragment：

public class EventFragment extends Fragment implements EventResponse {
private String latitude, longitude;
private static final String ARG_SECTION_NUMBER = "section_number";
private RecyclerView eventList;
private EventAdapter adapter;
private TextView ifNullEvents;
private final ArrayList<EventData> eventsData = new ArrayList<>();
private UserDataBase db;
private List<String> latLonList;
private ProgressBar progressBar;

public EventFragment() {
}


public static EventFragment newInstance(int sectionNumber) {
    EventFragment fragment = new EventFragment();
    Bundle args = new Bundle();
    args.putInt(ARG_SECTION_NUMBER, sectionNumber);
    fragment.setArguments(args);
    return fragment;
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.event_fragment, container, false);
    initView(rootView);
    db = new UserDataBase(getContext());
    checkLocationChanged();
    latLonList = db.getLatLon();
    latitude = latLonList.get(0);
    longitude = latLonList.get(1);
    String EVENT_BRITE_URL_PARSE = "MY_URL";
    String EVENT_BRITE_TOKEN = "MY_TOKEN";
    new EventBriteApi(this, getContext()).execute(EVENT_BRITE_URL_PARSE + EVENT_BRITE_TOKEN);
    setupRecyclerView();
    setLocationMessage();
    return rootView;
}

private void initView(View view) {
    eventList = (RecyclerView) view.findViewById(R.id.event_recycler_view);
    ifNullEvents = (TextView) view.findViewById(R.id.text_null_location);
    progressBar = (ProgressBar) view.findViewById(R.id.progress_bar_event);
}


private void checkLocationChanged() {
    if (WePrefs.isLocationChanged) {
        eventsData.clear();
        ifNullEvents.setText(getResources().getString(R.string.waiting_for_data));
        ifNullEvents.setVisibility(View.VISIBLE);
        progressBar.setVisibility(View.VISIBLE);
        WePrefs.setIsLocationChanged(false);

    } else {
        progressBar.setVisibility(View.GONE);
        ifNullEvents.setVisibility(View.GONE);
    }
    if (WePrefs.isNullEventLocation) {
        ifNullEvents.setText(getResources().getString(R.string.no_events_found));
        ifNullEvents.setVisibility(View.VISIBLE);
        progressBar.setVisibility(View.INVISIBLE);
        WePrefs.setIsNullEventLocation(false);
    }

}

private void setupRecyclerView() {
    eventList.setHasFixedSize(true);
    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity());
    linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
    eventList.setLayoutManager(linearLayoutManager);
    adapter = new EventAdapter(getActivity(), eventsData);
    adapter.setHasStableIds(true);
    eventList.setAdapter(adapter);

}

@Override
public void onResume() {
    checkLocationChanged();
    setLocationMessage();
    super.onResume();

}

private void setLocationMessage() {

    if (eventsData.isEmpty()) {
        ifNullEvents.setVisibility(View.VISIBLE);
        progressBar.setVisibility(View.VISIBLE);

    } else {
        ifNullEvents.setVisibility(View.GONE);
        progressBar.setVisibility(View.GONE);
    }
    progressBar.setVisibility(View.GONE);


}

@Override
public void getArray(ArrayList<EventData> data) {
    eventsData.clear();
    eventsData.addAll(new ArrayList<>(new LinkedHashSet<>(data)));
}

}

适配器：

ublic class EventAdapter extends RecyclerView.Adapter<EventAdapter.EventHolder> {
ArrayList<EventData> data;
Context context;

public EventAdapter(Context context, ArrayList<EventData> events) {
    this.context = context;
    data = events;
}

@Override
public EventHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    RelativeLayout layout = (RelativeLayout) LayoutInflater.from(parent.getContext()).inflate(R.layout.single_event_view, parent, false);
    return new EventAdapter.EventHolder(layout);
}

@Override
public void onBindViewHolder(EventHolder holder, int position) {
    holder.eventName.setText(data.get(position).getEventName());
    if (data.get(position).getEventImageUrl() != null) {
        Picasso.with(context).load(data.get(position).getEventImageUrl()).into(holder.eventPic);
    } else {
        holder.eventPic.setImageDrawable(ContextCompat.getDrawable(context, R.drawable.no_image));
    }
}

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

public class EventHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    TextView eventName;
    ImageView eventPic;
    RelativeLayout layout;

    public EventHolder(View itemView) {
        super(itemView);
        eventName = (TextView) itemView.findViewById(R.id.event_name);
        eventPic = (ImageView) itemView.findViewById(R.id.event_image);
        layout = (RelativeLayout) itemView.findViewById(R.id.event_layout);
        layout.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        //context.startActivity(new Intent(context, WebViewActivity.class));
    }
}
}

这些是我用于此类事情的一些java类。

无论如何，另一个问题是，当我更改位置（接收我的事件）时，我必须转到另一个选项卡，然后返回查看我的事件列表（我认为它需要重新创建视图）所以，因为我打电话给Resume，但它没有帮助。