编辑:我找到了解决方案。
我以错误的方式转换界面。
应该是:
( (IOnResultObtainedListener) adapter.getItem(i)).onResultObtained(response.getCompetition());
代替:
((IOnResultObtainedListener) CompetitionActivity.this).onResultObtained(response.getCompetition());
}
我有一个 ViewPager,其中包含三个 fragment 和一个列表。我需要用我的网络服务响应时获得的数据填充它们,但我不知道如何通知每个 fragment 。我试图在 Activity 和 Fragments 之间实现接口(interface),但出现此错误:
java.lang.ClassCastException:
com.cuatroochenta.mybets.home.mygames.newGame.CompetitionActivity
cannot be cast to
com.cuatroochenta.mybets.home.mygames.newGame.IOnResultObtainedListener
这是我的 Activity 代码:
public class CompetitionActivity extends MyBetsActionBarActivity implements ICompetitionsResponseListener {
private Toolbar toolbar;
private TabLayout tabLayout;
private ViewPager viewPager;
Handler handler;
IOnResultObtainedListener onResultObtainedListener;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle("Competiciones");
setSupportActionBar(toolbar);
handler = new Handler();
getSupportActionBar().setDisplayHomeAsUpEnabled(false);
viewPager = (ViewPager) findViewById(R.id.viewpager);
setupViewPager(viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
}
@Override
public void onResume() {
super.onResume();
doRequestCompetitions();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater menuInflater = getMenuInflater();
menuInflater.inflate(R.menu.search_menu, menu);
MenuItem searchItem = menu.findItem(R.id.action_search);
SearchManager searchManager = (SearchManager) this.getSystemService(Context.SEARCH_SERVICE);
SearchView searchView = null;
if (searchItem != null) {
searchView = (SearchView) searchItem.getActionView();
}
if (searchView != null) {
searchView.setSearchableInfo(searchManager.getSearchableInfo(this.getComponentName()));
}
return super.onCreateOptionsMenu(menu);
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(new PopularsFragment(), "Populares");
adapter.addFragment(new CategoriesFragment(), "Categorías");
adapter.addFragment(new NewsFragment(), "Nuevos");
viewPager.setOffscreenPageLimit(3);
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
@Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
@Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
@Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
private void doRequestCompetitions(){
if (NetworkUtils.isNetworkAvailable(this)) {
CompetitionsService competitionsService = new CompetitionsService();
competitionsService.setServiceUrl(url);
competitionsService.getCompetitionsAsync(new CompetitionsRequest(user, password), this);
} else {
InfoAlertManager.showInfoDialog(this, "Conexión requerida", "Aceptar");
}
}
@Override
public void onCompetitionsResponse(final CompetitionsResponse response) {
if (response.getCompetition() != null) {
Log.d("onCompetitionsResponse", response.getCompetition().toString());
// HERE IS WHEN I RECEIVE THE RESPONSE AND I SHOULD NOTIFY IT TO THE FRAGMENTS
handler.post(new Runnable() {
@Override
public void run() {
((IOnResultObtainedListener) CompetitionActivity.this).onResultObtained(response.getCompetition());
}
});
}
}
@Override
public void onError(ServiceResponseError serviceResponseError) {
Log.d("ServiceResponseError", serviceResponseError.getMessage());
}
public void setOnResultObtainedListener(IOnResultObtainedListener onResultObtainedListener){
this.onResultObtainedListener = onResultObtainedListener;
}
}
这是我的 fragment 代码之一:
public class PopularsFragment extends Fragment implements IOnResultObtainedListener {
RecyclerView rvPopular;
CompetitionAdapter mCompetitionAdapter;
public PopularsFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d("PopularsFragment", "onCreate");
}
@Override
public void onStart() {
super.onStart();
Log.d("MyBets", "PopularsFragment Visible");
}
@Override
public void onResume() {
super.onResume();
((CompetitionActivity)getActivity()).setOnResultObtainedListener(this);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_competitions, container, false);
rvPopular = (RecyclerView) rootView.findViewById(R.id.rvCompetitions);
rvPopular.setLayoutManager(new LinearLayoutManager(getActivity()));
rvPopular.setHasFixedSize(true);
return rootView;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
@Override
public void onResultObtained(Competition competition) {
mCompetitionAdapter = new CompetitionAdapter(getActivity(), competition, 0);
rvPopular.setAdapter(mCompetitionAdapter);
}
}
有什么想法吗?我已经搜索过类似的问题,但我没有找到任何有用的东西...... 希望你能帮助我。非常感谢!
最佳答案
您的CompetitionActivity
实现的接口(interface)不是IOnResultObtainedListener
,而是ICompetitionsResponseListener
。实现IOnResultObtainedListener
的是ViewPager下的Fragment。
fragment 的实例由 ViewPagerAdapter 保存为 mFragmentList
。因此,将其修饰符更改为默认(或公共(public)),您可以从类外部访问它。
final List<Fragment> mFragmentList = new ArrayList<>();
此外,您还必须将 ViewPagerAdapter 实例保存到字段变量而不是本地变量,以便在 setupViewPager 方法之外访问它:
private ViewPagerAdapter pagerAdapter;
private void setupViewPager(ViewPager viewPager) {
pagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
...
}
然后,代替这一行:
((IOnResultObtainedListener) CompetitionActivity.this).onResultObtained(response.getCompetition());
放置这段代码:
for (Fragment fragment : pagerAdapter.mFragmentList) {
((IOnResultObtainedListener) fragment).onResultObtained(response.getCompetition());
}
调用每个 fragment 的监听器。
关于android - Viewpager + 网络服务,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/33637888/