【发布时间】：2016-03-19 11:53:11
【问题描述】：
我目前面临的一个问题是，如果用户在他们的时间表中添加了一些内容，则应该在第二个标签Current Timetable 中的recyclerview 中刷新它。但是，它永远不会更新，用户必须返回主菜单，返回Timetables 活动，然后选择Current Timetable。我相信这与我的ViewPager 及其适配器有关。我只是看不出哪里出错了，我确信这是我想念的简单事情。请您修改我的代码以使其正常工作
这是我的代码： 浏览器类
public class Timetables extends AppCompatActivity{
TabLayout tabLayout;
ViewPager viewPager;
Context context;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.timetables);
viewPager = (ViewPager) findViewById(R.id.viewPager);
TimetablesAdapter timetablesAdapter = new TimetablesAdapter(getSupportFragmentManager(), Timetables.this);
viewPager.setAdapter(timetablesAdapter);
viewPager.setOffscreenPageLimit(2);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
//viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
//viewPager.setCurrentItem(tab.getPosition());
}
});
}
}
fragmentpageradapter 类：
public class TimestableAdapter extends FragmentPagerAdapter{
String tabNames[] = new String[] {"All timetables", "Current Timetable", "Expired"};
Context context;
public TimestableAdapter(FragmentManager fragmentManager, Context context){
super(fragmentManager);
this.context = context;
}
@Override
public Fragment getItem(int position) {
switch (position){
case 0:
return new AllTimetables();
case 1:
return new CurrentTimetables();
case 2:
return new ExpiredTimetables();
default:
return null;
}
}
@Override
public int getCount() {
return tabNames.length;
}
@Override
public CharSequence getPageTitle(int position) {
return tabNames[position];
}
}
这是CurrentTimetable 类：
public class CurrentTimetables extends Fragment {
RecyclerView recyclerView;
static MusicRecyclerAdapter adapter;
RecyclerView.LayoutManager layoutManager;
ArrayList<Timetables> list;
public CurrentTimetables(){
}
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.currenttimetable, container, false);
recyclerView = (RecyclerView) rootView.findViewById(R.id.timetablerecyclerView);
recyclerView.setHasFixedSize(true);
list = new ArrayList<Timetables>();
adapter = new MusicRecyclerAdapter(list, CurrentTimetables.this);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity().getApplicationContext());
linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.setAdapter(adapter);
tabBackground = new TabBackground(CurrentTimetables.this, list, spinnerItems, adapter, spinnerAdapter);
tabBackground.populateConditionsList();
inputs = new ArrayList<>();
populate();
return rootView;
}
@Override
public void onResume() {
super.onResume();
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
}
@Override
public void onStart() {
super.onStart();
}
public void populate(){
String dbURL = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
RequestQueue requestQueue = Volley.newRequestQueue(fragment.getActivity());
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest
(dbURL, new Response.Listener<JSONArray>(){
@Override
public void onResponse(JSONArray jsonArray) {
if(!list.isEmpty()){
list.clear();
}
try {
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
int timetableID = Integer.parseInt(jsonObject.getString("timetableID"));
String timetableName = jsonObject.getString("timetableName");
String subjectName = jsonObject.getString("subjectName");
Timetables timetables = new Timetables(timetableID, timetableName, subjectName);
list.add(timetables);
adapter.notifyDataSetChanged();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener(){
@Override
public void onErrorResponse(VolleyError volleyError) {
}
}
);
requestQueue.add(jsonArrayRequest);
}
}
真的意味着很多人可以帮助我
谢谢
【问题讨论】：
-
请发布您的 CurrentTimetables 片段类的代码
-
如果你有timetable的数据库，尝试在currentTimetable片段的onResume方法中刷新recyclerview。
-
哦，好吧，你的意思是在 onResume 中调用 populate 方法（这会用 db 中的值填充 recyclerview）？
-
它不起作用，我把它放在
onResume()- 仍然没有运气 -
在选项卡中，所有片段都将被调用一次，因此它的 oncreateview 和 onviewcreated 方法将在您切换片段时调用，其 onResume 方法将被调用。您应该检查它的生命周期以了解它。
标签： android android-fragments android-viewpager fragmentpageradapter