Develop Reference

Is it possible to get data from my listview onclick

Hi I have been working through several different tutorials on getting data from a sql database into a listview. I can add data, get data from database and populate the list view, and have a working onclick listener (will fire off a Toast message). However I can not get any data from the listview when clicked. I have tried different combinations of getitem and getItemAtPosition but they all return a empty string(blank toast). Would someone be kind enough to look at my code and tell me if what I am trying to do is possible. In my listview i have four items in each entry, I would like to either get the fourth item directly or get all the items (as string?) then I can pull out the data I need.
Thanks in advance for your time.
public class ListViewActivity extends Activity {
SQLiteHelper SQLITEHELPER;
SQLiteDatabase SQLITEDATABASE;
Cursor cursor;
SQLiteListAdapter ListAdapter ;
ArrayList<String> ID_ArrayList = new ArrayList<String>();
ArrayList<String> GENRE_ArrayList = new ArrayList<String>();
ArrayList<String> NAME_ArrayList = new ArrayList<String>();
ArrayList<String> URL_ArrayList = new ArrayList<String>();
ListView LISTVIEW;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list_view);
LISTVIEW = (ListView) findViewById(R.id.listView1);
SQLITEHELPER = new SQLiteHelper(this);
}
#Override
protected void onResume() {
ShowSQLiteDBdata() ;
super.onResume();
}
private void ShowSQLiteDBdata() {
SQLITEDATABASE = SQLITEHELPER.getWritableDatabase();
cursor = SQLITEDATABASE.rawQuery("SELECT * FROM demoTable1", null);
ID_ArrayList.clear();
GENRE_ArrayList.clear();
NAME_ArrayList.clear();
URL_ArrayList.clear();
if (cursor.moveToFirst()) {
do {
ID_ArrayList.add(cursor.getString(cursor.getColumnIndex(SQLiteHelper.KEY_ID)));
GENRE_ArrayList.add(cursor.getString(cursor.getColumnIndex(SQLiteHelper.KEY_Genre)));
NAME_ArrayList.add(cursor.getString(cursor.getColumnIndex(SQLiteHelper.KEY_Name)));
URL_ArrayList.add(cursor.getString(cursor.getColumnIndex(SQLiteHelper.KEY_Url)));
} while (cursor.moveToNext());
}
ListAdapter = new SQLiteListAdapter(ListViewActivity.this,
ID_ArrayList,
GENRE_ArrayList,
NAME_ArrayList,
URL_ArrayList
);
LISTVIEW.setAdapter(ListAdapter);
LISTVIEW.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
// String text = (String) LISTVIEW.getAdapter().getItem(position);
String text = (String) LISTVIEW.getItemAtPosition(position);
//String text = (String) lv.getItemAtPosition(0);
// Object item = (Object) LISTVIEW.getItemAtPosition(position);
Toast.makeText(getApplicationContext(), text, Toast.LENGTH_SHORT).show();
}
});
cursor.close();
}
}

LISTVIEW.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
String value1 = ID_ArrayList.get(position);
String value2 = GENRE_ArrayList.get(position);
String value3 = NAME_ArrayList.get(position);
String value4 = URL_ArrayList.get(position);
Toast.makeText(getApplicationContext(),value1+" "+value2+" "+value3+" "+value4, Toast.LENGTH_SHORT).show();
}
});

try to change the line
String text = (String) LISTVIEW.getItemAtPosition(position);
with
String text = (String) parent.getItemAtPosition(position);
this should be the way ListView works.
Also i suggest you to not use Capital Cases with variables, usually in Java is used a CamelCase convention. And also have a look at RecyclerView, that usually is implemented today much more than ListView, because allow a great level of customization

Pls use below code within listview setOnItemClickListener :-
String genreID = ID_ArrayList.get(position);
String genre = GENRE_ArrayList.get(position);
String genreName = NAME_ArrayList.get(position);
String genreUrl = URL_ArrayList.get(position);
Toast.makeText(getApplicationContext(), genreID+", "+genre+","+genreName+", "+genreUrl+", "+, Toast.LENGTH_SHORT).show();
its return render data of listview.

try this,
ShowSQLiteDBdata() in onCreate() instead of onResume() method

set textview onload and not on itemclick in a listview

I have a listview populated from a table with a simple adapter. Now, I can change the value of a textview if I click the list item, like this:
ArrayList<HashMap<String, String>> userList = controller.getOld();
// If users exists in SQLite DB
if (userList.size() != 0) {
// Set the User Array list in ListView
ListAdapter adapter = new SimpleAdapter(OldTips.this, userList, R.layout.old_tips, new String[] {
"userId", "tara","ora_meci" ,"echipa_acasa","echipa_deplasare","cota","pronostic","explicatii","rezultat"}, new int[] { R.id.userId, R.id.tara , R.id.ora_meci, R.id.echipa_acasa, R.id.echipa_deplasare, R.id.cota,R.id.pronostic,R.id.explicatii,R.id.rezultat});
final ListView myList = (ListView) findViewById(android.R.id.list);
myList.setAdapter(adapter);
myList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
// Object obj = myList.getAdapter().getItem(position);
// String value= obj.toString();
TextView textView = (TextView) view.findViewById(R.id.echipa_acasa);
// String nume_campanie = textView.getText().toString();
textView.setText("value of header text");
}
});
Question: is it possible to change the textview value onload or something like this and not onclick of the item from the listview?

android: how to delete a line from sql via ListView?

I managed to show a list from sqllite, now I want that when the user click on the item, the item will be deleted. the problem is that the item's ID number from the sql is different from the listview's ID. so how can I delete the selected item?
I mean this id:
public void onItemClick(AdapterView parent, View view,int position, long id)
is different from the item's ID from the sqllite.
thank you for help
Cursor resultSet = db.rawQuery("Select * from list ORDER BY `ID` DESC",null);
resultSet.moveToFirst();
final ListView listview = (ListView) findViewById(R.id.listView1);
ArrayList<HashMap<String, String>> mylistData = new ArrayList<HashMap<String, String>>();
String[] columnames = new String[] {"C1", "C2", "C3"};
int[] columnsR = new int[] {R.id.column1, R.id.column2, R.id.column3};
int x=0;
while(resultSet.moveToNext()){
HashMap<String,String> map = new HashMap<String, String>();
String d_weight = resultSet.getString(resultSet.getColumnIndex("weight"));
String d_date = resultSet.getString(resultSet.getColumnIndex("date"));
String d_id = resultSet.getString(resultSet.getColumnIndex("ID"));
x=0;
map.put(columnames[x],d_weight);
x++;
map.put(columnames[x],d_date);
x++;
map.put(columnames[x],d_id);
mylistData.add(map);
}
SimpleAdapter arrayAdapter = new SimpleAdapter(this, mylistData, R.layout.row,columnames , columnsR);
listview.setAdapter(arrayAdapter);
listview.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,int position, long id)
{
// how to delete? =[
}});

Would it not be easier to make an object that you fill with the data from your sql query for each entry? Then you just populate the listview with a list of these objects, which means that when one of the objects get clicked on the id will be stored inside the object. Then int position would have the same value as the position in your list of objects.
How does that sound?

android passing id from database to arraylist

i am doing a listview and getting data from database .. each view or row has its value from the database
but how to pass the id also from the database to the list view
so when i click one one view i get the id and do my thing like (delete ... where id = ...)
this how it looks
this is my code thank you :
private void setAdapter() {
dbHelper=new DatabaseHelper(this);
Cursor c = dbHelper.getcursor("M_table","M_title");
String s="";
Integer i=0;
ArrayList<String> values = new ArrayList<String>();
if (c != null ) {
if (c.moveToFirst()) {
do {
i++;
int Mid = c.getInt(c.getColumnIndex("Mid"));
String M_title = c.getString(c.getColumnIndex("M_title"));
values.add(M_title);
}while (c.moveToNext());
}
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,R.layout.listview,values);
setListAdapter(adapter);
adapter.notifyDataSetChanged();
}

first of all in you'll have to store the id in your listview XML file.have a field like this followed by your other fields.
<TextView
android:id="#+id/tv_Id"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
then in your adapter code,you will have to retrieve the id from this field and pass it to the next activity using a bundle.
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
String clickid = ((TextView) view.findViewById(R.id.tv_Id))
.getText().toString();
Bundle job_info = new Bundle();
id_info.putString("key", clickid);
Intent i = new Intent(CurrentActivity.this, NextActivity.class);
i.putExtras(id_info);
startActivity(i);
}

Android - ListView dynamic Buttons for each row calling dynamic listeners

I'm new to android, i've spent the last 2 days trying previous examples and online solutions but I just can't seem to get my head around it :(
I'm able to display a list view, parse some json from online and store a book title, book description and book ID and display this data in the listview. I want to be able to put a 'download' button in each row for the ListView, each button will correspond to its book ID on Click() and the action listener will download the book by appending that ID to a url.
e.g www.books.com/download_book1 or /download_book2....
Here is my code. Catalogue.java class
public class Catalogue extends ListActivity {
private JSONObject json;
private ListView lv;
private ArrayList<Integer> alKey = new ArrayList<Integer>();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState); //icicle
setContentView(R.layout.shelflist);
ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();
....
try{
JSONArray entries = json.getJSONArray("entries");
for(int i=0;i<entries.length();i++){
HashMap<String, String> map = new HashMap<String, String>();
JSONObject e = entries.getJSONObject(i);
alKey.add(e.getInt("key"));
map.put("id", String.valueOf(i));
map.put("title", "Title:" + e.getString("title"));
map.put("description", "Description: " + e.getString("description"));
mylist.add(map);
}
}catch(JSONException e) {
Log.e("log_tag", "Error parsing data "+e.toString());
}
ListAdapter adapter = new SimpleAdapter(this, mylist , R.layout.shelfrow,
new String[] { "title", "description" },
new int[] { R.id.item_title, R.id.item_subtitle });
setListAdapter(adapter);
lv = getListView();
lv.setTextFilterEnabled(true);
.....
This is as far as I get. I don't know how to add 1 button per row in the List and assign an action listener to each button.
I also have a shelfrow.xml file (textView, textView for item_title and item_subtitle) and a shelflist.xml file (ListView).
I have a shelf.xml file with

Basically you need to learn the concept of ListAdapter.
Here's the short story: picture an object that holds the data to be displayed inside a list, along with the way to display each line individually. That's your ListAdapter. Now take each individual line: it's a book with a title and an OnClickListener. It's rendered inside a View with a TextView (for the title) and a Button (for the OnClickListener). All you need to do is give one View to the adapter that will be used for each line, and a List of the books you want to be inside the list.
Here's some sample code. I hope it clears things up a bit
private class MyItemModel{ //that's our book
String title; // the book's title
String description;
long id;
OnClickListener listener = new OnClickListener(){ // the book's action
#Override
public void onClick(View v) {
// the default action for all lines
doSomethingWithTheBookTitleOrUniqueId(this);
}
};
}
private class MyListAdapter extends BaseAdapter{
View renderer;
List<MyItemModel> items;
// call this one and pass it layoutInflater.inflate(R.layout.my_list_item)
public MyListAdapter(View renderer) {
this.renderer = renderer;
}
// whenever you need to set the list of items just use this method.
// call it when you have the data ready and want to display it
public void setModel(List<MyItemModel> items){
this.items = items;
notifyDataSetChanged();
}
#Override
public int getCount() {
return items!=null?items.size():0;
}
#Override
public Object getItem(int position) {
return items!=null?items.get(position):null;
}
#Override
public long getItemId(int position) {
return items!=null?items.get(position).id:-1;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView==null){
convertView = renderer;
}
MyItemModel item = items.get(position);
// replace those R.ids by the ones inside your custom list_item layout.
TextView label = (TextView)convertView.findViewById(R.id.item_title);
label.setText(item.label);
Button button = (Button)convertView.findViewById(R.id.item_button);
button.setOnClickListener(item.listener);
return convertView;
}
}
In order to pass the List, instead of putting the data inside your list of hashmaps you can do this for instance (be careful, I also updated the MyItemModel and MyListAdapter to your need, added the id and description properties):
List<MyItemModel> myListModel = new ArrayList<MyItemModel>();
try{
JSONArray entries = json.getJSONArray("entries");
for(int i=0;i<entries.length();i++){
MyItemModel item = new MyItemModel();
JSONObject e = entries.getJSONObject(i);
alKey.add(e.getInt("key"));
item.id = i;
item.title = e.getString("title");
item.description = e.getString("description");
// you can change the button action at this point:
// item.onClickListener = new OnClickListener(){...};
myListModel.add(item);
}
}catch(JSONException e) {
Log.e("log_tag", "Error parsing data "+e.toString());
}
ListAdapter adapter = new MyListAdapter(getLayoutInflater().inflate(R.layout.shelfrow, this));
adapter.setModel(myListModel);
setListAdapter(adapter);
lv = getListView();
lv.setTextFilterEnabled(true);

You can create your own class extending ArrayAdapter that will hold your list and set onClickListener to the Button in each row.
But in getView method of your ArrayAdapter you have to create a new view every time.
for example - row layout
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="110dp"
android:background="#FFF"
android:layout_width="fill_parent">
<LinearLayout
android:layout_width="fill_parent"
android:background="#FFF"
android:orientation="vertical"
android:padding="2dp"
android:layout_height="110dp">
<TextView android:id="#+id/list_item_title"
android:background="#FFF"
android:layout_width="fill_parent"
android:layout_height="40dp"/>
<Button android:id="#+id/download_button"
android:gravity="center"
android:text="Download"
android:layout_height="35dp"/>
</LinearLayout>
</RelativeLayout>
and getView method in ArrayAdapter
private List<Map<String, String>> jsonMapList;
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View v = inflater.inflate(R.layout.list_item, null);
// here you set textview values (title and description)
// TextView title = (TextView) v.findViewById(R.id.list_item_title);
// title.setText('bla');
// and set OnClickListener
Button button = (Button) v.findViewById(R.id.download_button);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
downloadFile(getUrl(position));
}
});
return v;
}
// method that downloads file
private void downloadFile(String url) {}
// get url from your list by index
private String getUrl(int index) {
return jsonMapList.get(index).get("url");
}
Usage of Map is unnecessary, you could use any object you prefer.
In activity class
CustomAdapter listAdapter = new CustomAdapter(this, android.R.layout.simple_list_item_single_choice, jsonMapList);
setListAdapter(listAdapter);