我有5片段并用底部导航栏所示。让我们称之为第一片段是片段A.我从片段加载数据的使用凌空和使用再循环视图显示它。当我点击底部导航到另一片段（片段B）和点击返回片段A.数据是走
包含底部导航片段主要活动：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(isNetworkStatusAvialable (getApplicationContext())) {
bottomNavigationView=(BottomNavigationView)findViewById(R.id.main_nav);
frameLayout=(FrameLayout) findViewById(R.id.main_frame);
herbal= new herbal();
crude = new crude();
database=new database();
analysis=new analysis();
compound=new compound();
setFragment(herbal);
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
switch (menuItem.getItemId())
{
case R.id.nav_herbal:
setFragment(herbal);
return true;
case R.id.nav_crude:
setFragment(crude);
return true;
case R.id.nav_database:
setFragment(database);
return true;
case R.id.nav_analysis:
setFragment(analysis);
return true;
case R.id.nav_compound:
setFragment(compound);
return true;
default:
return false;
}
}
});
} else {
Toast.makeText(getApplicationContext(), "internet is not avialable", Toast.LENGTH_SHORT).show();
}
}
private boolean isNetworkStatusAvialable(Context context) {
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivityManager != null)
{
NetworkInfo netInfos = connectivityManager.getActiveNetworkInfo();
if(netInfos != null)
if(netInfos.isConnected())
return true;
}
return false;
}
private void setFragment(Fragment fragment) {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.main_frame,fragment);
fragmentTransaction.commit();
}
这是对recyclerview片段A的代码：
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.fragment_herbal, container, false);
herbalModels = new ArrayList<>();
kampoModels = new ArrayList<>();
searchHerbal = (EditText) rootView.findViewById(R.id.search_herbal);
searchHerbal.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
searchHerb();
}
});
loadData = (ProgressBar) rootView.findViewById(R.id.loadRecyclerView);
RequestQueue queue = MySingleton.getInstance(this.getActivity().getApplicationContext()).getRequestQueue();
sortData(rootView);
get20DataJamu();
get20DataKampo();
StartRecyclerViewJamu(rootView);
return rootView;
}
private void searchHerb() {
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
searchHerbs searchHerbs = new searchHerbs();
ft.replace(R.id.main_frame, searchHerbs);
ft.commit();
}
private void StartRecyclerViewKampo(View rootView) {
mRecyclerView = (RecyclerView) rootView.findViewById(R.id.recyclerview_herbal);
mRecyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(getActivity());
// use a linear layout manager
mRecyclerView.setLayoutManager(mLayoutManager);
kampoAdapter = new kampoAdapter(mRecyclerView, getActivity(), kampoModels);
mRecyclerView.setAdapter(kampoAdapter);
kampoAdapter.setOnLoadMoreListener(new OnLoadMoreListener() {
@Override
public void onLoadMore() {
kampoModels.add(null);
kampoAdapter.notifyItemInserted(kampoModels.size() - 1);
handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
kampoModels.remove(kampoModels.size() - 1);
kampoAdapter.notifyItemRemoved(kampoModels.size());
//add items one by one
int start = kampoModels.size();
int end = start + 20;
loadMoreKampo(start, end);
}
}, 5000);
}
});
}
private void loadMoreKampo(final int start, final int end) {
String url = "https://jsonplaceholder.typicode.com/photos";
JsonArrayRequest request = new JsonArrayRequest(url,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray jsonArray) {
Log.d(TAG, "Onresponse" + jsonArray.toString());
for (int i = start; i < end; i++) {
try {
JSONObject jsonObject = jsonArray.getJSONObject(i);
// Log.d(TAG,"jsonobject"+jsonObject);
kampoModels.add(
new kampoModel(
jsonObject.getString("title"),
"Khasiat",
jsonObject.getString("albumId"),
jsonObject.getString("id"),
jsonObject.getString("thumbnailUrl")
)
);
kampoAdapter.notifyItemInserted(kampoModels.size());
} catch (JSONException e) {
}
}
kampoAdapter.setLoaded();
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError volleyError) {
Log.d(TAG, "Onerror" + volleyError.toString());
}
});
MySingleton.getInstance(getActivity()).addToRequestQueue(request);
}
private void get20DataKampo() {
String url = "https://jsonplaceholder.typicode.com/photos";
JsonArrayRequest request = new JsonArrayRequest(url,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray jsonArray) {
Log.d(TAG, "Onresponsekampo" + jsonArray.toString());
Log.d(TAG, "lengthresponse" + jsonArray.length());
for (int i = 0; i < 20; i++) {
try {
JSONObject jsonObject = jsonArray.getJSONObject(i);
// Log.d(TAG,"jsonobject"+jsonObject);
kampoModels.add(
new kampoModel(
jsonObject.getString("title"),
"Khasiat",
jsonObject.getString("albumId"),
jsonObject.getString("id"),
jsonObject.getString("thumbnailUrl")
)
);
} catch (JSONException e) {
}
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError volleyError) {
Log.d(TAG, "Onerrorkampo" + volleyError.toString());
}
});
MySingleton.getInstance(getActivity()).addToRequestQueue(request);
}
private void StartRecyclerViewJamu(final View rootView) {
mRecyclerView = (RecyclerView) rootView.findViewById(R.id.recyclerview_herbal);
mRecyclerView.setVisibility(View.GONE);
mRecyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(getActivity());
// use a linear layout manager
mRecyclerView.setLayoutManager(mLayoutManager);
// create an Object for Adapter
mAdapter = new herbalAdapter(mRecyclerView, getActivity(), herbalModels);
mRecyclerView.setAdapter(mAdapter);
loadData.setVisibility(View.GONE);
mRecyclerView.setVisibility(View.VISIBLE);
mAdapter.notifyDataSetChanged();
mAdapter.setOnLoadMoreListener(new OnLoadMoreListener() {
@Override
public void onLoadMore() {
//add null , so the adapter will check view_type and show progress bar at bottom
herbalModels.add(null);
mAdapter.notifyItemInserted(herbalModels.size() - 1);
handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
// remove progress item
herbalModels.remove(herbalModels.size() - 1);
mAdapter.notifyItemRemoved(herbalModels.size());
//add items one by one
int start = herbalModels.size();
int end = start + 20;
loadMoreJamu(start, end);
}
}, 5000);
}
});
}
private void get20DataJamu() {
String url = "https://jsonplaceholder.typicode.com/posts";
JsonArrayRequest request = new JsonArrayRequest(url,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray jsonArray) {
Log.d(TAG, "Onresponse" + jsonArray.toString());
Log.d(TAG, "lengthonresponse" + jsonArray.length());
for (int i = 0; i < 20; i++) {
try {
JSONObject jsonObject = jsonArray.getJSONObject(i);
// Log.d(TAG,"jsonobject"+jsonObject);
herbalModels.add(
new herbalModel(
jsonObject.getString("title"),
"Khasiat",
jsonObject.getString("userId"),
jsonObject.getString("id"),
jsonObject.getString("body")
)
);
} catch (JSONException e) {
}
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError volleyError) {
Log.d(TAG, "Onerror" + volleyError.toString());
}
});
MySingleton.getInstance(getActivity()).addToRequestQueue(request);
}
private void loadMoreJamu(final int start, final int end) {
String url = "https://jsonplaceholder.typicode.com/posts";
JsonArrayRequest request = new JsonArrayRequest(url,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray jsonArray) {
Log.d(TAG, "Onresponse" + jsonArray.toString());
for (int i = start; i < end; i++) {
try {
JSONObject jsonObject = jsonArray.getJSONObject(i);
// Log.d(TAG,"jsonobject"+jsonObject);
herbalModels.add(
new herbalModel(
jsonObject.getString("title"),
"Khasiat",
jsonObject.getString("userId"),
jsonObject.getString("id"),
jsonObject.getString("body")
)
);
mAdapter.notifyItemInserted(herbalModels.size());
} catch (JSONException e) {
}
}
mAdapter.setLoaded();
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError volleyError) {
Log.d(TAG, "Onerror" + volleyError.toString());
}
});
MySingleton.getInstance(getActivity()).addToRequestQueue(request);
}
private void sortData(final View rootView) {
final Spinner spinner = (Spinner) rootView.findViewById(R.id.filter_herbal);
// Create an ArrayAdapter using the string array and a default spinner layout
List<categoriesHerbal> itemList = new ArrayList<categoriesHerbal>();
itemList.add(
new categoriesHerbal(
"1",
"Jamu"
)
);
itemList.add(
new categoriesHerbal(
"2",
"Kampo"
)
);
ArrayAdapter<categoriesHerbal> spinnerAdapter = new ArrayAdapter<categoriesHerbal>(getActivity(), android.R.layout.simple_spinner_item, itemList);
spinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// Specify the layout to use when the list of choices appears
// Apply the adapter to the spinner
spinner.setAdapter(spinnerAdapter);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
if (position == 0) {
categoriesHerbal selectedValue = (categoriesHerbal) parent.getItemAtPosition(position);
String categories = (String) selectedValue.getCategories();
String idCategories = (String) selectedValue.getIdCategories();
StartRecyclerViewJamu(rootView);
} else {
categoriesHerbal selectedValue = (categoriesHerbal) parent.getItemAtPosition(position);
String categories = (String) selectedValue.getCategories();
String idCategories = (String) selectedValue.getIdCategories();
StartRecyclerViewKampo(rootView);
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
}
试图改变自己的setFragment（）来，
private void setFragment(Fragment fragment) {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.main_frame,fragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
当你想回来，只是删除最后一个片段。