我有一项活动，在该活动中，我有一个持有四个片段的viewpager。在每个片段中都有一个自定义列表视图，当我尝试更新列表并执行notifyDataSetChanged（）时，它不会更改或更新屏幕上的列表。下次它操纵下一个列表成员。任何帮助人员如何解决它。 这是我的片段类，我尝试在onpostdelete方法中更新列表
public class StreamFragment extends Fragment implements Constants，SwipeRefreshLayout.OnRefreshListener，ItemInterface {
private static final String STATE_LIST = "State Adapter Data";
private static final int PROFILE_NEW_POST = 4;
Spinner mNavSpinner;
ListView mListView;
TextView mMessage;
ImageView mSplash;
SwipeRefreshLayout mItemsContainer;
FloatingActionButton mFabButton;
private ArrayList<Item> itemsList;
private StreamListAdapter itemsAdapter;
private String uniID;
private int category = 0;
private int itemId = 0;
private int arrayLength = 0;
private Boolean loadingMore = false;
private Boolean viewMore = false;
private Boolean restore = false;
public StreamFragment() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState != null) {
itemsList = savedInstanceState.getParcelableArrayList(STATE_LIST);
itemsAdapter = new StreamListAdapter(getActivity(), itemsList, this);
restore = savedInstanceState.getBoolean("restore");
itemId = savedInstanceState.getInt("itemId");
category = savedInstanceState.getInt("category");
} else {
itemsList = new ArrayList<Item>();
itemsAdapter = new StreamListAdapter(getActivity(), itemsList, this);
restore = false;
itemId = 0;
category = 0;
}
Bundle bundle = this.getArguments();
if(bundle!=null)
category = bundle.getInt("category", 0);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_stream, container, false);
mItemsContainer = (SwipeRefreshLayout) rootView.findViewById(R.id.container_items);
mItemsContainer.setOnRefreshListener(this);
mMessage = (TextView) rootView.findViewById(R.id.message);
mSplash = (ImageView) rootView.findViewById(R.id.splash);
mFabButton = (FloatingActionButton) rootView.findViewById(R.id.fabButton);
mFabButton.setImageResource(R.drawable.ic_action_new);
mListView = (ListView) rootView.findViewById(R.id.listView);
SharedPreferences preferences= PreferenceManager.getDefaultSharedPreferences(getActivity());
String uniname=preferences.getString("Uni","");
uniID = preferences.getString("UniID","");
mFabButton.attachToListView(mListView, new ScrollDirectionListener() {
@Override
public void onScrollDown() {
}
@Override
public void onScrollUp() {
}
}, new AbsListView.OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
int lastInScreen = firstVisibleItem + visibleItemCount;
if ((lastInScreen == totalItemCount) && !(loadingMore) && (viewMore) && !(mItemsContainer.isRefreshing())) {
if (App.getInstance().isConnected()) {
loadingMore = true;
getItems();
}
}
}
});
mListView.setAdapter(itemsAdapter);
mFabButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(getActivity(), NewItemActivity.class);
startActivityForResult(intent, STREAM_NEW_POST);
}
});
if (itemsAdapter.getCount() == 0) {
showMessage(getText(R.string.label_empty_list).toString());
} else {
hideMessage();
}
if (!restore) {
showMessage(getText(R.string.msg_loading_2).toString());
getItems();
}
return rootView;
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putBoolean("restore", true);
outState.putInt("itemId", itemId);
outState.putInt("category", category);
outState.putParcelableArrayList(STATE_LIST, itemsList);
}
@Override
public void onRefresh() {
if (App.getInstance().isConnected()) {
itemId = 0;
getItems();
} else {
mItemsContainer.setRefreshing(false);
}
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == STREAM_NEW_POST && resultCode == getActivity().RESULT_OK && null != data) {
itemId = 0;
getItems();
}
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
super.onCreateOptionsMenu(menu, inflater);
}
public void getItems() {
mItemsContainer.setRefreshing(true);
CustomRequest jsonReq = new CustomRequest(Request.Method.POST, METHOD_STREAM_GET, null,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
if (!loadingMore) {
itemsList.clear();
}
try {
arrayLength = 0;
if (!response.getBoolean("error")) {
itemId = response.getInt("itemId");
if (response.has("items")) {
JSONArray itemsArray = response.getJSONArray("items");
arrayLength = itemsArray.length();
if (arrayLength > 0) {
for (int i = 0; i < itemsArray.length(); i++) {
JSONObject itemObj = (JSONObject) itemsArray.get(i);
Item item = new Item(itemObj);
itemsList.add(item);
}
}
}
}
} catch (JSONException e) {
e.printStackTrace();
} finally {
loadingComplete();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
loadingComplete();
}
}) {
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
params.put("accountId", Long.toString(App.getInstance().getId()));
params.put("accessToken", App.getInstance().getAccessToken());
params.put("itemId", Integer.toString(itemId));
params.put("clientId", CLIENT_ID);
//params.put("category", Integer.toString(category));
params.put("universityId",uniID );
// params.put("category", uniID);
params.put("language", "en");
return params;
}
};
App.getInstance().addToRequestQueue(jsonReq);
}
public void loadingComplete() {
if (arrayLength == LIST_ITEMS) {
viewMore = true;
} else {
viewMore = false;
}
itemsAdapter.notifyDataSetChanged();
if (itemsAdapter.getCount() == 0) {
if (StreamFragment.this.isVisible()) {
showMessage(getText(R.string.label_empty_list).toString());
}
} else {
hideMessage();
}
loadingMore = false;
mItemsContainer.setRefreshing(false);
}
public void onCategoryChange(int cat) {
itemId = 0;
getItems();
category = cat;
}
public void report(int position) {
android.app.FragmentManager fm = getActivity().getFragmentManager();
PostReportDialog alert = new PostReportDialog();
Bundle b = new Bundle();
b.putInt("position", position);
b.putInt("reason", 0);
alert.setArguments(b);
alert.show(fm, "alert_dialog_post_report");
}
public void onPostReport(int position, int reasonId) {
final Item item = itemsList.get(position);
if (App.getInstance().isConnected()) {
Api api = new Api(getActivity());
api.postReport(item.getId(), reasonId);
} else {
Toast.makeText(getActivity(), getText(R.string.msg_network_error), Toast.LENGTH_SHORT).show();
}
}
public void remove(int position) {
android.app.FragmentManager fm = getActivity().getFragmentManager();
PostDeleteDialog alert = new PostDeleteDialog();
Bundle b = new Bundle();
b.putInt("position", position);
alert.setArguments(b);
alert.show(fm, "alert_dialog_post_delete");
}
public void onPostDelete(int position) {
final Item item = itemsList.get(position);
itemsList.remove(position);
itemsAdapter.notifyDataSetChanged();
if (mListView.getAdapter().getCount() == 0) {
showMessage(getText(R.string.label_empty_list).toString());
} else {
hideMessage();
}
if (App.getInstance().isConnected()) {
Api api = new Api(getActivity());
api.postDelete(item.getId());
} else {
Toast.makeText(getActivity(), getText(R.string.msg_network_error), Toast.LENGTH_SHORT).show();
}
}
public void onPostRemove(final int position) {
/** Getting the fragment manager */
android.app.FragmentManager fm = getActivity().getFragmentManager();
/** Instantiating the DialogFragment class */
PostDeleteDialog alert = new PostDeleteDialog();
/** Creating a bundle object to store the selected item's index */
Bundle b = new Bundle();
/** Storing the selected item's index in the bundle object */
b.putInt("position", position);
/** Setting the bundle object to the dialog fragment object */
alert.setArguments(b);
/** Creating the dialog fragment object, which will in turn open the alert dialog window */
alert.show(fm, "alert_dialog_post_delete");
}
public void onPostShare(final int position) {
final Item item = itemsList.get(position);
Api api = new Api(getActivity());
api.postShare(item);
}
public void action(int position) {
final Item item = itemsList.get(position);
if (item.getFromUserId() == App.getInstance().getId()) {
/** Getting the fragment manager */
android.app.FragmentManager fm = getActivity().getFragmentManager();
/** Instantiating the DialogFragment class */
MyPostActionDialog alert = new MyPostActionDialog();
/** Creating a bundle object to store the selected item's index */
Bundle b = new Bundle();
/** Storing the selected item's index in the bundle object */
b.putInt("position", position);
/** Setting the bundle object to the dialog fragment object */
alert.setArguments(b);
/** Creating the dialog fragment object, which will in turn open the alert dialog window */
alert.show(fm, "alert_my_post_action");
} else {
/** Getting the fragment manager */
android.app.FragmentManager fm = getActivity().getFragmentManager();
/** Instantiating the DialogFragment class */
PostActionDialog alert = new PostActionDialog();
/** Creating a bundle object to store the selected item's index */
Bundle b = new Bundle();
/** Storing the selected item's index in the bundle object */
b.putInt("position", position);
/** Setting the bundle object to the dialog fragment object */
alert.setArguments(b);
/** Creating the dialog fragment object, which will in turn open the alert dialog window */
alert.show(fm, "alert_post_action");
}
}
public void showMessage(String message) {
mMessage.setText(message);
mMessage.setVisibility(View.VISIBLE);
mSplash.setVisibility(View.VISIBLE);
}
public void hideMessage() {
mMessage.setVisibility(View.GONE);
mSplash.setVisibility(View.GONE);
}
public void onPostCreateChat(int position) {
final Item item = itemsList.get(position);
createChat(item.getFromUserId());
}
public void onPostFollow(int position) {
final Item item = itemsList.get(position);
Api api = new Api(getActivity());
api.profileFollow(item.getFromUserId());
}
public void createChat(final long profileId) {
if (App.getInstance().isConnected() && App.getInstance().getId() != 0) {
CustomRequest jsonReq = new CustomRequest(Request.Method.POST, METHOD_CHAT_NEW, null,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
if (!response.getBoolean("error")) {
Intent intent = new Intent(getActivity(), ChatActivity.class);
intent.putExtra("position", 0);
intent.putExtra("chatId", response.getInt("id"));
intent.putExtra("profileId", response.getLong("withUserId"));
intent.putExtra("chatTitle", response.getString("title"));
intent.putExtra("fromUserId", response.getLong("fromUserId"));
intent.putExtra("toUserId", response.getLong("toUserId"));
startActivityForResult(intent, 1);
} else {
Toast.makeText(getActivity(), getString(R.string.msg_chat_create_error), Toast.LENGTH_SHORT).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getActivity(), getString(R.string.error_data_loading), Toast.LENGTH_SHORT).show();
}
}) {
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
params.put("accountId", Long.toString(App.getInstance().getId()));
params.put("accessToken", App.getInstance().getAccessToken());
params.put("profileId", Long.toString(profileId));
return params;
}
};
int socketTimeout = 0;//0 seconds - change to what you want
RetryPolicy policy = new DefaultRetryPolicy(socketTimeout, 0, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
jsonReq.setRetryPolicy(policy);
App.getInstance().addToRequestQueue(jsonReq);
}
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
}
@Override
public void onDetach() {
super.onDetach();
}
}
答案 0 :(得分：1)
我会做这样的事情：
在活动：
中<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="container">
<div class="image">
</div>
<div class="slider">
<div class="title">Title</div>
<div class="text">Text</div>
</div>
</div>BaseFragment 应该扩展Fragment，并且有一个名为 updateList（）的方法。
BaseFragment visibleFragment = getViewPager().getItem(getPageAdapter.getCurrentItem());
在 BaseFragment 中：
visibleFragment.updateList();
// visibleFragment is the fragment visible to the user