I have a ListView on my android app. When click a ListView item and go to a new activity and when i press back button i land on a empty ListView. I dont get any data. Even if i restart the app i dont get any data on the ListView. It works only the first time i run the app. Do i have to override the onStop method and reset my ListView adapter? how do i fix this?
ListView activity
public class ViewGuidesActivity extends AppCompatActivity {
private static final String TAG = ViewGuidesActivity.class.getSimpleName();
private ProgressDialog pDialog;
private List<Guide> guideList = new ArrayList<Guide>();
private ListView listView;
private CustomListAdapter adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_guides);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
this.getSupportActionBar().setDisplayHomeAsUpEnabled(true);
listView = (ListView) findViewById(R.id.list);
adapter = new CustomListAdapter(this, guideList);
listView.setAdapter(adapter);
pDialog = new ProgressDialog(this);
// Showing progress dialog before making http request
pDialog.setMessage("Loading...");
pDialog.show();
// Creating volley request obj
JsonArrayRequest movieReq = new JsonArrayRequest(AppConfig.URL_GET_GUIDE_LIST,
new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
hidePDialog();
// Parsing json
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
Guide guide = new Guide();
guide.setNgno(obj.getString("ngno"));
guide.setEmail(obj.getString("email"));
guide.setName(obj.getString("name"));
// adding movie to movies array
guideList.add(guide);
} catch (JSONException e) {
e.printStackTrace();
}
}
// notifying list adapter about data changes
// so that it renders the list view with updated data
adapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.d(TAG, error.toString());
VolleyLog.d(TAG, "Error: " + error.getMessage());
hidePDialog();
}
});
// Adding request to request queue
AppController.getInstance().addToRequestQueue(movieReq);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapter, View view, int position, long id) {
Guide newGuide = guideList.get(position);
String email = newGuide.getEmail();
String ngno = newGuide.getNgno();
Intent i = new Intent(getApplicationContext(), GuideDetails.class);
i.putExtra("email", email);
i.putExtra("ngno", ngno);
startActivity(i);
}
});
}
private void hidePDialog() {
if (pDialog != null) {
pDialog.dismiss();
pDialog = null;
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
menu.getItem(1).setVisible(false);
menu.getItem(2).setVisible(false);
return true;
}
}
ListAdapter
public class CustomListAdapter extends BaseAdapter {
private Activity activity;
private LayoutInflater inflater;
private List<Guide> guideItems;
public CustomListAdapter(Activity activity, List<Guide> guideItems) {
this.activity = activity;
this.guideItems = guideItems;
}
#Override
public int getCount() {
return guideItems.size();
}
#Override
public Object getItem(int location) {
return guideItems.get(location);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.customrow, parent, false);
TextView ngno = (TextView) convertView.findViewById(R.id.txt_ListNgno);
TextView name = (TextView) convertView.findViewById(R.id.txt_ListName);
TextView email = (TextView) convertView.findViewById(R.id.txt_ListEmail);
// getting guide data for the row
Guide g = guideItems.get(position);
//thumbNail.setImageUrl(m.getThumbnailUrl(), imageLoader);
ngno.setText(g.getNgno());
name.setText(g.getName());
email.setText(g.getEmail());
return convertView;
}
}
how do i fix this issue?
Related
I am following a tutorial about multiple choice listview in android.
When executing the app, the listview shows some items, not all of them. After clicking on the listview, it shows all items.
I want to know where is the reason of that issue.
This is the code for MainActivity class:
public class MainActivity extends AppCompatActivity {
Toolbar toolbar;
FloatingActionButton fab;
ListView list;
TextView txt_menu;
String dipilih;
private static final String TAG = MainActivity.class.getSimpleName();
Adapter adapter;
ProgressDialog pDialog;
List<Data> itemList = new ArrayList<Data>();
// Sesuaikan dengan IP Address PC/LAptop atau ip emulator bawaan android 10.0.2.2
private static String url = "https://.../test/menu.php";
public static final String TAG_NAMA = "nama";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
fab = (FloatingActionButton) findViewById(R.id.fab);
list = (ListView) findViewById(R.id.list_menu);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String checkbox = "";
for (Data hold : adapter.getAllData()) {
if (hold.isCheckbox()) {
checkbox += "\n" + hold.getMenu();
}
}
if (!checkbox.isEmpty()) {
dipilih = checkbox;
} else {
dipilih = "Anda Belum Memilih Menu.";
}
formSubmit(dipilih);
}
});
callVolley();
adapter = new Adapter(this, (ArrayList<Data>) itemList);
list.setAdapter(adapter);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
adapter.setCheckBox(position);
}
});
}
private void formSubmit(String hasil){
AlertDialog.Builder dialog = new AlertDialog.Builder(this);
LayoutInflater inflater = getLayoutInflater();
View dialogView = inflater.inflate(R.layout.form_submit, null);
dialog.setView(dialogView);
dialog.setIcon(R.mipmap.ic_launcher);
dialog.setTitle("Menu Yang Dipilih");
dialog.setCancelable(true);
txt_menu = (TextView) dialogView.findViewById(R.id.txt_menu);
txt_menu.setText(hasil);
dialog.setNeutralButton("CLOSE", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
dialog.show();
}
private void callVolley(){
itemList.clear();
// menapilkan dialog loading
pDialog = new ProgressDialog(this);
pDialog.setMessage("Loading...");
showDialog();
// membuat request JSON
JsonArrayRequest jArr = new JsonArrayRequest(url, new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
hideDialog();
// Parsing json
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
Data item = new Data();
item.setMenu(obj.getString(TAG_NAMA));
// menambah item ke array
itemList.add(item);
} catch (JSONException e) {
e.printStackTrace();
}
}
// notifikasi adanya perubahan data pada adapter
adapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
hideDialog();
}
});
// menambah request ke request queue
AppController.getInstance().addToRequestQueue(jArr);
}
private void showDialog() {
if (!pDialog.isShowing())
pDialog.show();
}
private void hideDialog() {
if (pDialog.isShowing())
pDialog.dismiss();
}
}
And this is the Adapter class:
public class Adapter extends BaseAdapter {
private Context activity;
private ArrayList<Data> data;
private static LayoutInflater inflater = null;
private View vi;
private ViewHolder viewHolder;
public Adapter(Context context, ArrayList<Data> items) {
this.activity = context;
this.data = items;
inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
return data.size();
}
#Override
public Object getItem(int i) {
return i;
}
#Override
public long getItemId(int i) {
return i;
}
#Override
public View getView(int position, View view, ViewGroup viewGroup) {
vi = view;
final int pos = position;
Data items = data.get(pos);
if(view == null) {
vi = inflater.inflate(R.layout.list_row, null);
viewHolder = new ViewHolder();
viewHolder.checkBox = (CheckBox) vi.findViewById(R.id.cb);
viewHolder.menu = (TextView) vi.findViewById(R.id.nama_menu);
vi.setTag(viewHolder);
}else {
viewHolder = (ViewHolder) view.getTag();
viewHolder.menu.setText(items.getMenu());
}
if(items.isCheckbox()){
viewHolder.checkBox.setChecked(true);
} else {
viewHolder.checkBox.setChecked(false);
}
return vi;
}
public ArrayList<Data> getAllData(){
return data;
}
public void setCheckBox(int position){
Data items = data.get(position);
items.setCheckbox(!items.isCheckbox());
notifyDataSetChanged();
}
public class ViewHolder{
TextView menu;
CheckBox checkBox;
}
}
If you need other code parts to detect the problem, please let me know.
EDIT
First launch
After clicking on the listview
The problem is this bit of your code in your adapter's getView() callback:
if(view == null) {
...
}else {
...
viewHolder.menu.setText(items.getMenu());
}
What's happening here is that you're only caling setText() when the item view is recycled by the ListView. The reason everything shows up after you click a checkbox is that the ListView rebinds everything when you call notifyDataSetChanged().
You should call this method outside of the if/else statement so that it is executed every time.
if(view == null) {
...
}else {
...
}
viewHolder.menu.setText(items.getMenu());
I think the issue you are having is coming from the getView() method in your Adapter class.
Since you are using a ViewHolder to recycle objects you are first checking if the exist first before creating them if(view == null). But, you are only creating them and not assigning the TextView objects a String value. You only do that once the object has already been created. So, when you click on an item, you are calling notifyDataSetChanged causing the list to be updated. Then the values are set in the `TextView.
So try this instead: put the line viewHolder.menu.setText(items.getMenu()); outside the conditional statement:
#Override
public View getView(int position, View view, ViewGroup viewGroup) {
vi = view;
final int pos = position;
Data items = data.get(pos);
if(view == null) {
vi = inflater.inflate(R.layout.list_row, null);
viewHolder = new ViewHolder();
viewHolder.checkBox = (CheckBox) vi.findViewById(R.id.cb);
viewHolder.menu = (TextView) vi.findViewById(R.id.nama_menu);
vi.setTag(viewHolder);
}else {
viewHolder = (ViewHolder) view.getTag();
}
viewHolder.menu.setText(items.getMenu());
if(items.isCheckbox()){
viewHolder.checkBox.setChecked(true);
} else {
viewHolder.checkBox.setChecked(false);
}
return vi;
}
try this once
adapter = new Adapter(this, (ArrayList) itemList);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
adapter.setCheckBox(position);
}
});
list.setAdapter(adapter);
}
set adapter at the end
This is my Fragment in navigation view, it is opened as default when I clicked an item in navigation view and return back to this fragment the items in lists are doubled for example in list it has apple when i press back it shows two apples
public class AllProductsActivity extends Fragment {
private static final String TAG = MainActivity.class.getSimpleName();
private String category_id;
// Movies json url
private String url ;
private ProgressDialog pDialog;
private List<Movie> movieList=new ArrayList<Movie>() ;
private ListView listView;
private CustomListAdapter adapter;
public AllProductsActivity() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Bundle bundle=getArguments();
category_id = bundle.getString("IDS");
View rootView = inflater.inflate(R.layout.category_layout, container, false);
listView = (ListView) rootView.findViewById(R.id.categories_list);
adapter = new CustomListAdapter(getActivity(), movieList);
listView.setAdapter(adapter);
category_id = bundle.getString("IDS");
VerifyURL();
return rootView;
}
private void VerifyURL() {
if (category_id.equals("no_product")) {
url = "http://192.168.43.149/Newfolder/gap.php";
DownloadJSON();
}else{
url = "http://192.168.43.149/Newfolder/gap.php?category_id=" + category_id;
DownloadJSON();
}
}
private void DownloadJSON(){
pDialog=new
ProgressDialog(getActivity());
// Showing progress dialog before making http request
pDialog.setMessage("Loading...");
pDialog.show();
// Creating volley request obj
JsonArrayRequest movieReq = new JsonArrayRequest(url,
new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
hidePDialog();
// Parsing json
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
Movie movie = new Movie();
movie.setTitle(obj.getString("name"));
movie.setThumbnailUrl(obj.getString("image"));
movie.setRating(obj.getString("price"));
movie.setYear(obj.getString("description"));
// adding movie to movies array
movieList.add(movie);
} catch (JSONException e) {
e.printStackTrace();
}
}
// notifying list adapter about data changes
// so that it renders the list view with updated data
adapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
hidePDialog();
}
});
// Adding request to request queue
AppController.getInstance().addToRequestQueue(movieReq);
}
#Override
public void onDestroy() {
super.onDestroy();
hidePDialog();
}
private void hidePDialog() {
if (pDialog != null) {
pDialog.dismiss();
pDialog = null;
} }}
This is my Adapter class where it opens a Activity i want to open a Fragment I already changed get Fragment manager to the get child Fragment manager but it does not work
public class CustomListAdapter extends BaseAdapter {
private Activity activity;
private LayoutInflater inflater;
private List<Movie> movieItems;
HashMap<String, String> m = new HashMap<String, String>();
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
public CustomListAdapter(Activity activity, List<Movie> movieItems) {
this.activity = activity;
this.movieItems = movieItems;
}
#Override
public int getCount()
{
return movieItems.size();
}
#Override
public Object getItem(int location) {
return movieItems.get(location);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
if (inflater == null)
inflater = (LayoutInflater) activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null)
convertView = inflater.inflate(R.layout.all_products, null);
if (imageLoader == null)
imageLoader = AppController.getInstance().getImageLoader();
NetworkImageView thumbNail = (NetworkImageView) convertView
.findViewById(R.id.PI1);
ImageButton AddcarT=(ImageButton) convertView.findViewById(R.id.product_add_cart);
TextView title = (TextView) convertView.findViewById(R.id.PN1);
TextView rating = (TextView) convertView.findViewById(R.id.PD1);
TextView genre = (TextView) convertView.findViewById(R.id.PD2);
// getting movie data for the row
final Movie m = movieItems.get(position);
// thumbnail image
thumbNail.setImageUrl(m.getThumbnailUrl(), imageLoader);
// title
title.setText(m.getTitle());
// rating
rating.setText("Rating: " + String.valueOf(m.getRating()));
// genre
genre.setText(m.getYear());
// release year
convertView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
// Get the position
Movie m = movieItems.get(position);
Intent intent = new Intent(activity, ProductsViewActivity.class);
// Pass all data rank
intent.putExtra("rank", m.getTitle());
intent.putExtra("flag", m.getThumbnailUrl());
activity.startActivity(intent);
}
});
AddcarT.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
// Get the position
Movie m = movieItems.get(position);
Toast.makeText(activity, m.getTitle(), Toast.LENGTH_LONG).show();
// Pass all data rank
}
});
return convertView;}
}
If you're not calling your api multiple times to use pagination, call movieList.clear() or movieList = new ArrayList<>(); before adding data into it.
So your code will be:-
// Checking of movieList is not null
if(movieList != null) {
movieList.clear();
} else {
movieList = new ArrayList<>();
}
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
Movie movie = new Movie();
movie.setTitle(obj.getString("name"));
movie.setThumbnailUrl(obj.getString("image"));
movie.setRating(obj.getString("price"));
movie.setYear(obj.getString("description"));
// adding movie to movies array
movieList.add(movie);
} catch (JSONException e) {
e.printStackTrace();
}
}
In onCreateView() method, clear your list.
movieList.clear();
use this:
if (adapter==null) {
prod = new ArrayList<>();
adapter = new ProductsAdapter(prod, getActivity());
if (Constants.isNetworkAvailable(getActivity())){
recyclerView.setLayoutManager(GlayoutManager);
recyclerView.setAdapter(adapter);
}else {
Constants.showToast(getActivity(),"No Internet!!");
recyclerView.setLayoutManager(GlayoutManager);
recyclerView.setAdapter(adapter);
adapter.notifyDataSetChanged();
}
}else{
recyclerView.setLayoutManager(GlayoutManager);
recyclerView.setAdapter(adapter);
adapter.notifyDataSetChanged();
}
Simply clear the list before adding data into ArrayList. It means when you click on the back press it will clear first and then insert data into the list. So you always get an updated list.
list.clear()
The code below works fine. It populates a list with values from a JSON response and will open a new activity on selection of any of the items, as well as displaying the number of the item.
My question is how to have the selected item open an activity with the specific information from that item. Example: I select "Bob" from the List, I am taken to a new activity with the name of Bob, his email, and his phone. Or any other values that the JSON might have sent. If I select "George" it will do the same, but with the details for George.
I attempted unsuccessfully to do this on my own. Any help is appreciated.
Details.java code:
public class Details extends AppCompatActivity implements AdapterView.OnItemClickListener {
// Log tag
private static final String TAG = Details.class.getSimpleName();
private static String url = "removed";
private List<LoadUsers> detailList = new ArrayList<LoadUsers>();
private ListView listView;
private CustomListAdapter adapter;
private Button ShowDetailsButton;
private Button AddDetails;
private ProgressDialog pDialog;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.details_view);
listView = (ListView) findViewById(R.id.lv);
adapter = new CustomListAdapter(this, detailList);
listView.setAdapter(adapter);
listView.setOnItemClickListener(this);
ShowDetailsButton = (Button) findViewById(R.id.show_details);
AddDetails = (Button) findViewById(R.id.add_details);
// Progress dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
pDialog.setMessage("Loading...");
// changing action bar color
// getActionBar().setBackgroundDrawable(
// new ColorDrawable(Color.parseColor("#1b1b1b")));
ShowDetailsButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
detailList.clear();
// Showing progress dialog before making http request
showPDialog();
// Creating volley request obj
JsonArrayRequest detailsReq = new JsonArrayRequest(url,
new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
hidePDialog();
// Parsing json
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
LoadUsers details = new LoadUsers();
details.setTitle(obj.getString("name"));
details.setThumbnailUrl(obj.getString("image"));
details.setEmail(obj.getString("email"));
details.setPhone(obj.getString("phone"));
// adding to array
detailList.add(details);
} catch (JSONException e) {
e.printStackTrace();
}
}
// notifying list adapter about data changes
// so that it renders the list view with updated data
adapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
hidePDialog();
}
});
// Adding request to request queue
AppController.getInstance().addToRequestQueue(detailsReq);
}
});
AddDetails.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(Details.this, MoreDetails.class);
startActivity(i);
}
});
}
private void showPDialog() {
if (!pDialog.isShowing())
pDialog.show();
}
private void hidePDialog() {
if (pDialog.isShowing())
pDialog.dismiss();
}
public void onDestroy() {
super.onDestroy();
hidePDialog();
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(this, "Item Clicked: " + position, Toast.LENGTH_SHORT).show();
Intent i = new Intent(Details.this, onDetailsSelect.class);
startActivity(i);
}
}
CustomListAdapter.java code:
public class CustomListAdapter extends BaseAdapter {
public Activity activity;
private LayoutInflater inflater;
private List<LoadUsers> usersItems;
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
public CustomListAdapter(Activity activity, List<LoadUsers> usersItems) {
this.activity = activity;
this.usersItems = usersItems;
}
#Override
public int getCount() {
return usersItems.size();
}
#Override
public Object getItem(int location) {
return usersItems.get(location);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
if (inflater == null)
inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null)
convertView = inflater.inflate(R.layout.list_row, null);
if (imageLoader == null)
imageLoader = AppController.getInstance().getImageLoader();
NetworkImageView thumbNail = (NetworkImageView) convertView.findViewById(R.id.thumbnail);
TextView title = (TextView) convertView.findViewById(R.id.title);
TextView email = (TextView) convertView.findViewById(R.id.lvemail);
TextView phone = (TextView) convertView.findViewById(R.id.lvphone);
// getting user data for the row
LoadUsers m = usersItems.get(position);
// thumbnail image
thumbNail.setImageUrl(m.getThumbnailUrl(), imageLoader);
// title
title.setText(m.getTitle());
// email
email.setText("Email: " + String.valueOf(m.getEmail()));
// phone
phone.setText("Phone: " + String.valueOf(m.getPhone()));
return convertView;
}
}
New Activity that is being opened on selection of item:
onDetailsSelect.java:
public class onDetailsSelect extends AppCompatActivity {
Toolbar toolbar;
ActionBarDrawerToggle mActionBarDrawerToggle;
DrawerLayout drawerLayout;
private TextView title, email, phone;
private List<LoadUsers> usersItems;
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_onuserselect);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
NetworkImageView thumbNail = (NetworkImageView) findViewById(R.id.thumbnail);
title = (TextView) findViewById(R.id.title);
email = (TextView) findViewById(R.id.lvemail);
phone = (TextView) findViewById(R.id.lvphone);
}
}
Modify your onItemClick like that:
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(this, "Item Clicked: " + position, Toast.LENGTH_SHORT).show();
TextView title = (TextView) view.findViewById(R.id.title);
String title_text = title.getText().toString();
TextView email = (TextView) view.findViewById(R.id.lvemail);
String email_text = email.getText().toString();
TextView phone = (TextView) view.findViewById(R.id.lvphone);
String phone_text = phone.getText().toString();
Intent i = new Intent(Details.this, onDetailsSelect.class);
i.putExtra("title_intent", title_text);
i.putExtra("email_intent", email_text);
i.putExtra("phone_intent", phone_text);
startActivity(i);
}
And retrieve the intent values in onDetailsSelect Activity, in onCreate:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.detail);
Intent i = getIntent();
String title = i.getStringExtra("title_intent");
String email = i.getStringExtra("email_intent");
String phone = i.getStringExtra("phone_intent");
}
You can pass your ArrayList and item position on which you have clicked in the ListView, to the new activity like this --
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
String item_position = String.valueOf(position);
ArrayList<ListRowItem> full_listitem = listitem;
Intent intent = new Intent(context,SecondActivity.class);
Bundle extras = new Bundle();
extras.putString(CRRNT_ROW_NUMBER, item_position);
extras.putSerializable(LISTITEM, full_listitem);
intent.putExtras(extras);
startActivity(intent);
}
});
In your 2nd Activity, you have to receive these using the below code --
Intent intent = getIntent();
Bundle extras = intent.getExtras();
item_position = extras.getString(FirstActivity.CRRNT_ROW_NUMBER);
listitem = (ArrayList<ListRowItem>)extras.getSerializable(FirstActivity.LISTITEM);
position = Integer.parseInt(item_position);
currentlistitem = listitem.get(position);
String a = currentlistitem.getA();
String b = currentlistitem.getB();
For all these implementations, you have to implement Serializable interface in both your Activities and also in the LoadUsers (Getter/Setter) class.
Hope this helps!
I am getting NullPointerException in the activity where I am using adapter.notifyDataSetChanged();
Basically in the activity i am parsing the data and I am using the adapter of where the data needs to be setin the ListItems.
The code of the MainActivity -
public class SearchResultActivityOne extends AppCompatActivity {
private static final String url = "http://sikkimexpress.itstunner.com/api/newssearch/a";
private boolean enableBackNavigation;
String TAG = "";
private ProgressDialog pDialog;
private CustomListSearchAdapter adapter;
public static final String KEY_HEADURL = "news_url";
public static final String KEY_DETAILS = "news_details";
public static final String KEY_TITLE = "news_title";
String imageURL = "", title = "", description = "";
private List<Movie> movieList = new ArrayList<Movie>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search_result);
android.support.v7.widget.Toolbar toolbar = (android.support.v7.widget.Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
adapter.notifyDataSetChanged();
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
onBackPressed();
}
});
if (enableBackNavigation) {
// toolbar.setNavigationIcon(R.drawable.ic_back);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
onBackPressed();
}
});
}
// pDialog = new ProgressDialog(SearchResultActivityOne.this);
// pDialog.setMessage("Loading...Please Wait...");
// pDialog.setCancelable(false);
// pDialog.show();
JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
hidePDialog();
try {
JSONArray jsonArray = response.getJSONArray("HomeNews");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject homenews = jsonArray.getJSONObject(i);
Movie movie = new Movie();
movie.setNewsId(homenews.getString("NewsId"));
movie.setDateTime(homenews.getString("DateTime"));
movie.setNewsType(homenews.getString("NewsType"));
movie.setTitle(homenews.getString("Title"));
movie.setDescription(homenews.getString("Description"));
movie.setThumbnailUrl(homenews.getString("MainImageThumbnail"));
movieList.add(movie);
}
} catch (JSONException exception){
exception.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
hidePDialog();
}
});
AppController.getInstance().addToRequestQueue(request);
}
public void onDestroy() {
super.onDestroy();
hidePDialog();
}
private void hidePDialog() {
if (pDialog != null) {
pDialog.dismiss();
pDialog = null;
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_about_us:
Intent intent = new Intent(SearchResultActivityOne.this, AboutUs.class);
startActivity(intent);
return true;
case R.id.action_terms_of_use:
Intent intent_two = new Intent(SearchResultActivityOne.this, TermsUse.class);
startActivity(intent_two);
return true;
case R.id.action_privacy_policy:
Intent intent_three = new Intent(SearchResultActivityOne.this, PrivacyPolicy.class);
startActivity(intent_three);
return true;
case R.id.action_contact_us:
Intent intent_four = new Intent(SearchResultActivityOne.this, ContactUs.class);
startActivity(intent_four);
case R.id.action_search:
default:
return super.onOptionsItemSelected(item);
}
}
}
The CustomListViewAdapter
public class CustomListSearchAdapter extends BaseAdapter{
private Activity activity;
private LayoutInflater inflater;
private List<Movie> movieItems;
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
public CustomListSearchAdapter(Activity activity, List<Movie> movieItems) {
this.activity = activity;
this.movieItems = movieItems;
}
#Override
public int getCount() {
return movieItems.size();
}
#Override
public Object getItem(int location) {
return movieItems.get(location);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
if (inflater == null)
inflater = (LayoutInflater) activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null)
convertView = inflater.inflate(R.layout.list_row, null);
if (imageLoader == null)
imageLoader = AppController.getInstance().getImageLoader();
NetworkImageView thumbNail = (NetworkImageView) convertView.findViewById(R.id.thumbnail);
TextView title = (TextView) convertView.findViewById(R.id.title);
TextView desciption = (TextView) convertView.findViewById(R.id.desciption);
Movie m = movieItems.get(position);
thumbNail.setImageUrl(m.getThumbnailUrl(), imageLoader);
String text = Html.fromHtml(m.getTitle()).toString();
title.setText(text);
String text_two = Html.fromHtml(m.getDescription()).toString();
desciption.setText(text_two);
return convertView;
}
}
Your adapter object is not initialized yet so the notifyDatasetChanged() will raise a NullPointerException.
You'll need something along the lines of
adapter = new CustomListSearchAdapter(SearchResultActivityOne.this, movieList);
//Set the adapter to your ListView
Before you call adapter.notifyDatasetChanged() in your onCreate() method.
But I suspect you'll want to call notifyDatasetChanged() in the onResponse() when your movieList actually has items. Also, what is the point of having an adapter without a ListView?
I think you are missing some code. Initialize your ListView and adapter first. Something like this
ListView listView = (ListView) findById(R.id.list);
adapter = new CustomListSearchAdapter(SearchResultActivityOne.this, movieList);
listView.setAdapter(adapter);
You have to initialize your adapter:
adapter = new CustomListSearchAdapter();
Then set it on the list view
listview.setAdapter(adapter);
Update 1
In onCreate method:
ListView myListView = (ListView) findViewById(R.id.myListView);
CustomListSearchAdapter adapter = new CustomListSearchAdapter(... arguments ...);
myListView.setAdapter(adapter);
Then use this list view to set your adapter
Hello guys I have this problem, I want my app to refresh or update the listview items upon clicking a specific spinner item. here is the screenshot
and I have no idea on what I'm gonna do, and this is my code so far :(
public class ViewGrade extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
private ListView mylistView;
private String subj_code = "";
private String subj_code_lab = "";
private Spinner spinTerm;
private List<GradeList> gradeList = new ArrayList<GradeList>();
private GradeAdapter arrayAdapter;
private ProgressDialog pDialog;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_grade);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
spinTerm = (Spinner) findViewById(R.id.spinTerm);
String[] Term = new String[]{"Prelim", "Midterm", "Tentative Final"};
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, Term);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinTerm.setAdapter(adapter);
SharedPreferences preferences = getSharedPreferences("MyApp", MODE_PRIVATE);
subj_code = preferences.getString("code", "UNKNOWN");
subj_code_lab = preferences.getString("code_lab", "UNKNOWN");
mylistView = (ListView) findViewById(R.id.list);
arrayAdapter = new GradeAdapter(this, gradeList);
mylistView.setAdapter(arrayAdapter);
new loadGrades().execute();
}
public class loadGrades extends AsyncTask<Void, Void, Void>{
String term = spinTerm.getSelectedItem().toString();
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(ViewGrade.this);
// Showing progress dialog before making http request
pDialog.setMessage("Loading...");
pDialog.show();
}
#Override
protected Void doInBackground(Void... params) {
String url = null;
try {
url = "http://192.168.22.3/MobileClassRecord/getGrade.php?subj_code="+ URLEncoder.encode(subj_code, "UTF-8")+"&term="+URLEncoder.encode(term, "UTF-8");
}catch (UnsupportedEncodingException e){
e.printStackTrace();
}
ServiceHandler jsonParser = new ServiceHandler();
String json = jsonParser.makeServiceCall(url, ServiceHandler.GET);
Log.e("Response; ", "> " + json);
if (json != null){
try {
JSONObject object = new JSONObject(json);
if (object != null){
JSONArray grade_array = object.getJSONArray("grade");
for (int i = 0; i < grade_array.length(); i++){
JSONObject grade = (JSONObject) grade_array.get(i);
GradeList grade_list = new GradeList();
grade_list.setName(grade.getString("stud_name"));
grade_list.setGrade(grade.getString("grade"));
grade_list.setRemark(grade.getString("remark"));
gradeList.add(grade_list);
}
}
arrayAdapter.notifyDataSetChanged();
}catch (JSONException e){
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
pDialog.dismiss();
}
}
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_view_grade, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case android.R.id.home:
Intent intent = new Intent(ViewGrade.this, SpecificClassRecord.class);
startActivity(intent);
return true;
case R.id.action_add_grade:
Intent intent1 = new Intent(ViewGrade.this, Grade.class);
startActivity(intent1);
}
return super.onOptionsItemSelected(item);
}
}
adapter.notifydatasetChanged() or if you know the specific item inserted/removed, just use adapter.notifyitemInserted/Removed etc.
Add this code in your onClickListener for spinner
Override onItemClick() listener method of the spinner,then inside the method you call adapter.notifydatasetChanged() of the listview
spinTerm.setOnItemSelectedListener(new OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
// change the adapter values if your list is being changedin anyway
arrayAdapter.notifydatasetChanged();
}
#Override
public void onNothingSelected(AdapterView<?> parentView) {
// your code here
}
});