尝试从sqlite加载数据并在viewpager上显示它并没有太大成功。
我有一个带有两个选项卡的viewpager，它们应该根据作为newInstance参数传递的tag_id来保存数据。还有一个操作栏导航微调器，其中包含用于根据county_id显示的过滤器数据的县列表。
能够从服务器获取数据并将其保存在sqlite数据库中，但显示它是个问题。数据不会在viewpager的第一页上显示，但它存在于sqlite中。第二个数据是唯一一个加盖的数据。
以下是我的实施;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Parcelable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.app.ListFragment;
import android.support.v4.app.LoaderManager.LoaderCallbacks;
import android.support.v4.content.Loader;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v4.widget.SwipeRefreshLayout.OnRefreshListener;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBar.OnNavigationListener;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.ContextThemeWrapper;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import com.android.volley.AuthFailureError;
import com.android.volley.DefaultRetryPolicy;
import com.android.volley.NetworkError;
import com.android.volley.NoConnectionError;
import com.android.volley.ParseError;
import com.android.volley.Response;
import com.android.volley.ServerError;
import com.android.volley.TimeoutError;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.app.adapter.CustomCountySpinnerAdapter;
import com.app.adapter.TendersAdapter;
import com.app.database.DBFunctions;
import com.app.externallib.AppController;
import com.app.model.CountyModel;
import com.app.model.PostsModel;
import com.app.utils.AppConstants;
import com.app.utils.PostsListLoader;
import com.nhaarman.listviewanimations.appearance.simple.SwingBottomInAnimationAdapter;
import com.viewpagerindicator.TabPageIndicator;
public class PublicTendersFragment extends Fragment{
private static List<PubliTenders> public_tenders;
public PublicTendersFragment newInstance(String text) {
PublicTendersFragment mFragment = new PublicTendersFragment();
Bundle mBundle = new Bundle();
mBundle.putString(AppConstants.TEXT_FRAGMENT, text);
mFragment.setArguments(mBundle);
return mFragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
public_tenders = new ArrayList<PubliTenders>();
public_tenders.add(new PubliTenders(14, "County"));
public_tenders.add(new PubliTenders(15, "National"));
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final Context contextThemeWrapper = new ContextThemeWrapper(
getActivity(), R.style.StyledIndicators);
LayoutInflater localInflater = inflater
.cloneInContext(contextThemeWrapper);
View v = localInflater.inflate(R.layout.fragment_tenders, container,
false);
FragmentPagerAdapter adapter = new TendersVPAdapter(
getFragmentManager());
ViewPager pager = (ViewPager) v.findViewById(R.id.pager);
pager.setAdapter(adapter);
TabPageIndicator indicator = (TabPageIndicator) v
.findViewById(R.id.indicator);
indicator.setViewPager(pager);
return v;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setHasOptionsMenu(true);
}
class TendersVPAdapter extends FragmentPagerAdapter{
public TendersVPAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Parcelable saveState() {
return null;
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return Tenders.newInstance(public_tenders.get(position).tag_id);
case 1:
return Tenders.newInstance(public_tenders.get(position).tag_id);
default:
return null;
}
}
@Override
public CharSequence getPageTitle(int position) {
return public_tenders.get(position).tender_type.toUpperCase(Locale
.getDefault());
}
@Override
public int getCount() {
return public_tenders.size();
}
}
public class PubliTenders {
public int tag_id;
public String tender_type;
public PubliTenders(int tag_id, String tender_type) {
this.tag_id = tag_id;
this.tender_type = tender_type;
}
}
public static class Tenders extends ListFragment implements
OnNavigationListener, LoaderCallbacks<ArrayList<PostsModel>> {
boolean mDualPane;
int mCurCheckPosition = 0;
// private static View rootView;
private SwipeRefreshLayout swipeContainer;
private ListView lv;
private View rootView;
private DBFunctions mapper;
private CustomCountySpinnerAdapter spinadapter;
private TendersAdapter mTendersAdapter;
private static final String ARG_TAG_ID = "tag_id";
private int tag_id;
private int mycounty;
private static final int INITIAL_DELAY_MILLIS = 500;
private static final String DEBUG_TAG = "BlogsFragment";
private final String TAG_REQUEST = "BLOG_TAG";
private JsonArrayRequest jsonArrTendersRequest;
// private OnItemSelectedListener listener;
public static Tenders newInstance(int tag_id) {
Tenders fragment = new Tenders();
Bundle b = new Bundle();
b.putInt(ARG_TAG_ID, tag_id);
fragment.setArguments(b);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
tag_id = getArguments().getInt(ARG_TAG_ID);
}
@Override
public void onStart() {
super.onStart();
getLoaderManager().initLoader(0, null, this);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_headlines_blog,
container, false);
swipeContainer = (SwipeRefreshLayout) rootView
.findViewById(R.id.swipeProjectsContainer);
lv = (ListView) rootView.findViewById(android.R.id.list);
lv.setOnScrollListener(new AbsListView.OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view,
int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
int topRowVerticalPosition = (lv == null || lv
.getChildCount() == 0) ? 0 : lv.getChildAt(0)
.getTop();
swipeContainer.setEnabled(topRowVerticalPosition >= 0);
}
});
swipeContainer.setOnRefreshListener(new OnRefreshListener() {
@Override
public void onRefresh() {
fetchPublicTenders(mycounty);
}
});
swipeContainer.setColorSchemeResources(R.color.blue_dark,
R.color.irdac_green, R.color.red_light,
R.color.holo_red_light);
return rootView;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setHasOptionsMenu(true);
mapper = new DBFunctions(getActivity());
mapper.open();
// initialize AB Spinner
populateSpinner();
fetchPublicTenders(mycounty);
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("curChoice", mCurCheckPosition);
}
private void populateSpinner() {
try {
List<CountyModel> counties = new ArrayList<CountyModel>();
counties = mapper.getAllCounties();
ActionBar actBar = ((ActionBarActivity) getActivity())
.getSupportActionBar();
actBar.setDisplayShowTitleEnabled(true);
actBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);
spinadapter = new CustomCountySpinnerAdapter(getActivity(),
android.R.layout.simple_spinner_dropdown_item, counties);
actBar.setListNavigationCallbacks(spinadapter, this);
} catch (NullPointerException exp) {
}
}
@Override
public Loader<ArrayList<PostsModel>> onCreateLoader(int arg0,
Bundle arg1) {
Log.v(DEBUG_TAG, "On Create Loader");
return new PostsListLoader(getActivity(), mycounty, tag_id);
}
@Override
public void onLoadFinished(Loader<ArrayList<PostsModel>> arg0,
ArrayList<PostsModel> data) {
// System.out.println("results " + data.size());
addToAdapter(data);
}
@Override
public void onLoaderReset(Loader<ArrayList<PostsModel>> arg0) {
lv.setAdapter(null);
}
@Override
public boolean onNavigationItemSelected(int pos, long arg1) {
CountyModel mo = spinadapter.getItem(pos);
this.mycounty = mo.getId();
refresh(mo.getId());
return false;
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
TextView txtTitle = (TextView) v.findViewById(R.id.tender_title);
TextView txtRefNo = (TextView) v.findViewById(R.id.ref_no);
TextView txtExpiryDate = (TextView) v
.findViewById(R.id.expiry_date);
TextView txtOrg = (TextView) v.findViewById(R.id.dept_or_org);
Intent intTenderFullDetails = new Intent(getActivity(),
TenderDetailsActivity.class);
intTenderFullDetails.putExtra(TenderDetailsActivity.TENDER_TITLE,
txtTitle.getText().toString().trim());
intTenderFullDetails.putExtra(TenderDetailsActivity.TENDER_REF_NO,
txtRefNo.getText().toString().trim());
intTenderFullDetails.putExtra(
TenderDetailsActivity.TENDER_EXPIRY_DATE, txtExpiryDate
.getText().toString().trim());
intTenderFullDetails.putExtra(TenderDetailsActivity.TENDER_ORG,
txtOrg.getText().toString().trim());
// intTenderFullDetails.putExtra(TenderDetailsActivity.TENDER_DESC,
// Lorem);
startActivity(intTenderFullDetails);
}
private void fetchPublicTenders(final int county_id) {
swipeContainer.setRefreshing(true);
Uri.Builder builder = Uri.parse(AppConstants.postsUrl).buildUpon();
builder.appendQueryParameter("tag_id", Integer.toString(tag_id));
System.out.println("fetchPublicTenders with tag_id " + tag_id
+ " and county_id " + county_id);
jsonArrTendersRequest = new JsonArrayRequest(builder.toString(),
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
if (response.length() > 0) {
for (int i = 0; i < response.length(); i++) {
try {
JSONObject tender_item = response
.getJSONObject(i);
mapper.createPost(
tender_item.getInt("id"),
tender_item.getInt("tag_id"),
tender_item.getInt("county_id"),
tender_item.getInt("sector_id"),
tender_item.getString("title"),
tender_item.getString("slug"),
tender_item.getString("content"),
tender_item
.getString("reference_no"),
tender_item
.getString("expiry_date"),
tender_item
.getString("organization"),
tender_item
.getString("image_url"),
tender_item
.getString("created_at"));
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
swipeContainer.setRefreshing(false);
refresh(county_id);
}
} else {
if (swipeContainer.isShown()) {
swipeContainer.setRefreshing(false);
}
try {
Toast.makeText(getActivity(),
"Sorry! No results found",
Toast.LENGTH_LONG).show();
} catch (NullPointerException npe) {
System.out.println(npe);
}
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
if (error instanceof NetworkError) {
try {
Toast.makeText(
getActivity(),
"Network Error. Cannot refresh list",
Toast.LENGTH_SHORT).show();
} catch (NullPointerException npe) {
System.err.println(npe);
}
if (swipeContainer.isShown()) {
swipeContainer.setRefreshing(false);
}
refresh(county_id);
} else if (error instanceof ServerError) {
try {
Toast.makeText(
getActivity(),
"Problem Connecting to Server. Try Again Later",
Toast.LENGTH_SHORT).show();
} catch (NullPointerException npe) {
System.err.println(npe);
}
if (swipeContainer.isShown()) {
swipeContainer.setRefreshing(false);
}
} else if (error instanceof AuthFailureError) {
} else if (error instanceof ParseError) {
} else if (error instanceof NoConnectionError) {
try {
Toast.makeText(getActivity(),
"No Connection", Toast.LENGTH_SHORT)
.show();
} catch (NullPointerException npe) {
System.err.println(npe);
}
} else if (error instanceof TimeoutError) {
try {
Toast.makeText(
getActivity()
.getApplicationContext(),
"Timeout Error. Try Again Later",
Toast.LENGTH_SHORT).show();
} catch (NullPointerException npe) {
System.err.println(npe);
}
}
if (swipeContainer.isShown()) {
swipeContainer.setRefreshing(false);
}
}
}) {
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
HashMap<String, String> headers = new HashMap<String, String>();
headers.put("Accept", "application/json");
return headers;
}
};
// Set a retry policy in case of SocketTimeout & ConnectionTimeout
// Exceptions. Volley does retry for you if you have specified the
// policy.
jsonArrTendersRequest.setRetryPolicy(new DefaultRetryPolicy(
(int) TimeUnit.SECONDS.toMillis(20),
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
jsonArrTendersRequest.setTag(TAG_REQUEST);
AppController.getInstance().addToRequestQueue(jsonArrTendersRequest);
}
public void refresh(int county_id) {
Bundle b = new Bundle();
b.putInt("myconty", county_id);
if (isAdded()) {
getLoaderManager().restartLoader(0, b, this);
}
}
private void addToAdapter(ArrayList<PostsModel> plist) {
mTendersAdapter = new TendersAdapter(rootView.getContext(), plist);
SwingBottomInAnimationAdapter swingBottomInAnimationAdapter = new SwingBottomInAnimationAdapter(
mTendersAdapter);
swingBottomInAnimationAdapter.setAbsListView(lv);
assert swingBottomInAnimationAdapter.getViewAnimator() != null;
swingBottomInAnimationAdapter.getViewAnimator()
.setInitialDelayMillis(INITIAL_DELAY_MILLIS);
setListAdapter(swingBottomInAnimationAdapter);
mTendersAdapter.notifyDataSetChanged();
}
}
}
这是PostsListLoader类
import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.support.v4.content.AsyncTaskLoader;
import com.app.database.DBFunctions;
import com.app.model.PostsModel;
public class PostsListLoader extends AsyncTaskLoader<ArrayList<PostsModel>> {
private DBFunctions mapper;
private ArrayList<PostsModel> myPostsModel;
private int county_id;
private int tag_id;
public PostsListLoader(Context context, int county_id, int tag_id) {
super(context);
mapper = new DBFunctions(getContext());
mapper.open();
this.county_id = county_id;
this.tag_id = tag_id;
}
@Override
public ArrayList<PostsModel> loadInBackground() {
String query_string = AppConstants.KEY_COUNTY_ID + " = " + county_id
+ " AND " + AppConstants.KEY_TAG_ID + " = " + tag_id;
myPostsModel = mapper.getPosts(query_string);
return myPostsModel;
}
@Override
public void deliverResult(ArrayList<PostsModel> data) {
if (isReset()) {
// An async query came in while the loader is stopped. We
// don't need the result.
if (data != null) {
onReleaseResources(data);
}
}
List<PostsModel> oldNews = data;
myPostsModel = data;
if (isStarted()) {
// If the Loader is currently started, we can immediately
// deliver its results.
super.deliverResult(data);
}
// At this point we can release the resources associated with
// 'oldNews' if needed; now that the new result is delivered we
// know that it is no longer in use.
if (oldNews != null) {
onReleaseResources(oldNews);
}
}
/**
* Handles a request to start the Loader.
*/
@Override
protected void onStartLoading() {
if (myPostsModel != null) {
// If we currently have a result available, deliver it
// immediately.
deliverResult(myPostsModel);
}
if (takeContentChanged() || myPostsModel == null) {
// If the data has changed since the last time it was loaded
// or is not currently available, start a load.
forceLoad();
}
}
/**
* Handles a request to stop the Loader.
*/
@Override
protected void onStopLoading() {
// Attempt to cancel the current load task if possible.
cancelLoad();
}
/**
* Handles a request to cancel a load.
*/
@Override
public void onCanceled(ArrayList<PostsModel> news) {
super.onCanceled(news);
// At this point we can release the resources associated with 'news'
// if needed.
onReleaseResources(news);
}
/**
* Handles a request to completely reset the Loader.
*/
@Override
protected void onReset() {
super.onReset();
// Ensure the loader is stopped
onStopLoading();
// At this point we can release the resources associated with 'apps'
// if needed.
if (myPostsModel != null) {
onReleaseResources(myPostsModel);
myPostsModel = null;
}
}
/**
* Helper function to take care of releasing resources associated with an
* actively loaded data set.
*/
protected void onReleaseResources(List<PostsModel> news) {
}
}
我可能做错了什么？
任何帮助将不胜感激。
由于