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
Related
hello i need some help ... i write this code but i am little confused when i add book to my fav it store to fav when i click on un fav there in fav list the book are still there in that activity until i don't close the activity when i reopen that fav activity the book are removed from there i want to add code that can refresh by self at that time when i un fav the book ... please help me out
public class Favrt extends AppCompatActivity implements AdapterView.OnItemClickListener {
ListView viewF;
Books_Adapter fav_adapter;
String[] name, links, author;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_favrt);
fetch_fav();
fav_adapter = new Books_Adapter(this, name, links, author);
viewF = (ListView) findViewById(R.id.favView);
viewF.setAdapter(fav_adapter);
viewF.setOnItemClickListener(this);
}
public void fetch_fav(){
SQLiteDatabase database = openOrCreateDatabase("Pdf_books",MODE_PRIVATE,null);
Cursor db_cursor = database.rawQuery("select * from favourite", null);
name = new String[db_cursor.getCount()];
links = new String[db_cursor.getCount()];
author = new String[db_cursor.getCount()];
int i =0;
if (db_cursor.moveToLast()){
do {
name[i] = db_cursor.getString(db_cursor.getColumnIndex("name"));
links[i] = db_cursor.getString(db_cursor.getColumnIndex("links"));
author[i] = db_cursor.getString(db_cursor.getColumnIndex("author"));
i++;
}while (db_cursor.moveToPrevious());
}
database.close();
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent web = new Intent(this, web_activity.class);
web.putExtra("url", links[position]);
startActivity(web);
}
#Override
public void onContentChanged() {
super.onContentChanged();
View empty = findViewById(R.id.empty);
ListView list = (ListView) findViewById(R.id.favView);
list.setEmptyView(empty);
}
}
Try fav_adapter.notifyDataSetChanged() after changing your list items (in this case, when your favorites are changed).
You have to update adapter. to do so fav_adapter.notifyDataSetChanged(). which will make changes to listview.
make function in activity where you do such things like remove from db and update list data.
thanks for your help
I'm trying populate a spinner with data from an embedded database, and everything seems right:
public ArrayList<String[]> getCountries()
{
ArrayList<String[]> array = new ArrayList<>();
String columnas[] = new String[]{"COUNTRY","COUNTRYCODE"};
Cursor c = db.query("countryCodT",columnas,null,null,null,null,null);
if(c.moveToFirst()){
do{
String[] obj = new String[2];
obj[0]=c.getString(0);
obj[1]=c.getString(1);
array.add(obj);
}while(c.moveToNext());
c.close();
db.close();
}
return array;
}
with this code the spinner is populated:
public void popSpinnerC(){
BDCountries bdCountries = new BDCountries(this);
final ArrayList<String[]> dataGot = bdCountries.getCountries();
ArrayAdapter<String[]> dataAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_dropdown_item,dataGot);
spnCountry.setAdapter(dataAdapter);
spnCountry.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
String listId = Integer.toString(i);
strCounty = listId + dataGot.get(i)[0] + dataGot.get(i)[1];
msgData.setText(strCounty);
}
#Override
public void onNothingSelected(AdapterView<?> adapterView) {
}
});
}
the spinner text shown is wrong, the data amount is correct, when something is selected is shown the right information in a text view with test purposes, how can I correct it?
Results:
The spinner option list is a list of string arrays rather than strings so it is printing toString() of each string array as a spinner item.
Look at your getCountries() method. It is returning ArrayList<String[]> instead of ArrayList<String>.
this is a succesor to this question
At first everything worked fine but after 2 deletes the misery starts. The database entries start with ID 1, then 2 and so on. Lets say I have three database entries. The listview IDs for these three entries are 2,1 and 0.
The database entries are 1,2 and 3. 1 and 2 will be deleted with the onitemclicklistener but since the listview doesn´t have an ID 3, the corresponding database entry will never ever be deleted.
So the question is, how can I "sync" those two IDs?
Listview-Class
public class anzeigen extends AppCompatActivity {
private static final String TAG = anlegen.class.getSimpleName();
private static final String FILENAME = TAG + ".kdf";
private List valueList = new ArrayList<String>();
final VorgangDataSource dataSource = new VorgangDataSource(this);
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_anzeigen);
Log.d(TAG,"Die Datenquelle wird geöffnet!");
dataSource.open();
final List<vorgangsdaten> vorgangsdatenList = dataSource.getAllVorgangsDaten();
final ArrayAdapter<vorgangsdaten> VorgangArrayAdapter = new ArrayAdapter<>(
this,
R.layout.mylistlayout,
vorgangsdatenList
);
final ListView lv = (ListView)findViewById(R.id.listView);
lv.setAdapter(VorgangArrayAdapter);
lv.setItemsCanFocus(false);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String s_id = String.valueOf(id);
Log.d(s_id,"id_in_onitem");
String p_id = String.valueOf(position);
Log.d(p_id,"position_on_item");
int pos = position;
vorgangsdatenList.remove(pos);
dataSource.deleteRow(id);
VorgangArrayAdapter.notifyDataSetChanged();
}
});
//ActionBar Costumization
android.support.v7.app.ActionBar ab = getSupportActionBar();
ab.setIcon(R.drawable.search1);
ab.setDisplayShowHomeEnabled(true);
ab.setDisplayUseLogoEnabled(true);
}
#Override
protected void onDestroy() {
super.onDestroy();
dataSource.close();
}
}
deleteRow-Method:
public void deleteRow(long id){
String s_id;
s_id = String.valueOf(id);
Log.d(s_id,"id_value");
database.delete(VorgangDbHelper.TABLE_VORGAENGE_LIST,VorgangDbHelper.COLUMN_ID + " = ?", new String[] {s_id});
long deleteID = database.delete(VorgangDbHelper.TABLE_VORGAENGE_LIST,VorgangDbHelper.COLUMN_ID + " = ?", new String[] {s_id});
String s_del = String.valueOf(deleteID);
Log.d(s_del,"delete_row_value");
}
If you need more code just let me know :)
You have no synchronicity between your Database and the ListView items.
When selecting the data, select the ID from the table, and keep it in memory as well.
Since vorgangsdaten looks german or sweden, I am having trouble understanding the meaning of those words. The ListView has its own "id" for each item, to keep a list of them shown, and the rest "hidden". What you must do is have an Object with details that are syncronized with the database, and when a list item is clicked, the "list id" is used to query an Object and delete from the database.
An example would be:
ArrayList<MyObject> arrayListData = new ArrayList<>();
ArrayList<String> arrayListNames = new ArrayList<>();
MyObject stuffs = database.query(); // In here, fetch the data
/* I am simplifing the MyObject to [String name, String aValue, int aNumber] */
for(MyObject s: stuffs){
arrayListData.add(s);
arrayListNames.add(s.name);
}
arrayAdapter = new ArrayAdapter<String>(
this,
android.R.layout.simple_list_item_1,
arrayListNames
);
listView.setOnItemClickListener(
new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
MyObject thing = arrayListData.get(position);
database.delete(thing.aNumber);
}
}
);
listView.setAdapter(arrayAdapter);
After trying Bonattis answer and experimenting a little bit I found another answer.
deleteRow-Method
public void deleteRow(long id){
String s_id; //String for long id
s_id = String.valueOf(id); //assign String value of id
String s_rowId = null; //String for rowid
long rowId = 0;
long deleteId = 0;
String s_deleteId = null;
Log.d(s_id,"id_value");
Cursor cursor = database.query(VorgangDbHelper.TABLE_VORGAENGE_LIST,columns,null,null,null,null,null);
if(cursor.moveToFirst()) {
s_rowId = cursor.getString(cursor.getColumnIndex(VorgangDbHelper.COLUMN_ID));
rowId = Long.parseLong(s_rowId);
deleteId = rowId + id;
s_deleteId = String.valueOf(deleteId);
Log.d(s_rowId,"rowID");
Log.d(s_deleteId,"deleteID");
}
database.delete(VorgangDbHelper.TABLE_VORGAENGE_LIST,VorgangDbHelper.COLUMN_ID + " = ?", new String[] {s_deleteId});
}
How does it work now?
So the deleteRow-Method(dRM) gets the id of the first database entry (s_rowId) and converts it to long (rowId).
Now I take the long id passed from the listview and add it to rowId which is my deleteId. With this I have the correct database value to what I clicked in the listview and can pass it over to database.delete
I'm trying to save text from the selected item of a ListView in OnItemClick.
I've tried so many different methods to no avail, I think I'm missing something really stupidly obvious here...
SnakesListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String choice = SnakesListView.getItemAtPosition(position).toString();
Intent intent = new Intent(SnakeList.this, SnakeProfile.class);
intent.putExtra("SelectedSnakeName", choice);
startActivity(intent);
}
});
The data is being displayed fine, I just can't seem to reference it.
The line causing the exception:
String choice = SnakesListView.getItemAtPosition(position).toString();
Full code for this activity
public class SnakeList extends Activity {
ListView SnakesListView;
Cursor cursor;
Button NewSnakeBtn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_snake_list);
SnakesListView = (ListView) findViewById(R.id.SnakesListView);
NewSnakeBtn = (Button) findViewById(R.id.NewSnake);
SQLiteDatabase db = openOrCreateDatabase("snakeDB", Context.MODE_PRIVATE, null); // ACCESSES DB
cursor = db.rawQuery("SELECT name FROM snakes", null); // SETS cursor TO RESULTS OF QUERY
List<String> SnakeNamesList = new ArrayList<String>();
ArrayAdapter SnakeNamesAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, SnakeNamesList);
SnakeNamesList.clear(); // REMOVES ANY NAMES CURRENTLY IN NAME ARRAY TO AVOID DUPLICATES
SnakesListView.setAdapter(SnakeNamesAdapter);
if (cursor.moveToFirst()) {
cursor.moveToFirst(); // MOVES CURSOR TO FIRST POSITION
do SnakeNamesList.add(cursor.getString(0)); // RETURNS STRING FROM FIRST COLUMN (NAME)
while (cursor.moveToNext());
}
NewSnakeBtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
startActivity(new Intent(SnakeList.this, NewSnake.class));
}
});
SnakesListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String choice = SnakesListView.getItemAtPosition(position).toString();
Intent intent = new Intent(SnakeList.this, SnakeProfile.class);
intent.putExtra("SelectedSnakeName", choice);
startActivity(intent);
}
});
}
No use of referencing the ListView; you can get the value from adapter itself.
Change
String choice = SnakesListView.getItemAtPosition(position).toString();
to
String choice = SnakeNamesAdapter.getItem(position).toString();
declare the string arraylist(SnakeNamesList) as global variable and
change
String choice = SnakesListView.getItemAtPosition(position).toString();
to
String choice = SnakeNamesList.get(position);
public class ConnectDatabase extends Activity {
private SimpleDBAdapter mDbHelper;
private ListView list;
private String[] values;
private String[] list1;
private int i=0;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
list=(ListView )findViewById(R.id.simpleListView);
mDbHelper = new SimpleDBAdapter(ConnectDatabase.this);
mDbHelper.createDatabase();
mDbHelper.open();
values = mDbHelper.getEditTextValue();
mDbHelper.close();
for(i=0;i<10;i++) {
String tempvalue;
tempvalue=values[i];
list1[i]=tempvalue;
Log.v("log_tag"," tempvalue "+tempvalue);
Log.v("log_tag", "list1 is"+list1[i]);
//Log.v("log_tag"," list1"+list1[i]);
}
list.setAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, values));
//list.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
//list.setTextFilterEnabled(true);
list.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// When clicked, show a toast with the TextView text
Toast.makeText(getApplicationContext(),
((TextView) view).getText(), Toast.LENGTH_SHORT).show();
/*for(int i=0;i<values.length;i++) {
String templist=values[i];
list1[i]=templist;
}*/
String fname=values[position];
Log.v("log_tag", "The fname is"+ fname);
Intent intent=new Intent(ConnectDatabase.this, Userinfo.class);
intent.putExtra("FirstName",fname );
startActivity(intent);
}
});
// to remove the last comma
}
}
Here I am doing ListView from SQLite database and want to display in ListView with only the first 10 ListView rows at the time but I get the error at the line list1[i]=tempvalue; so I can't copy array here anyone can help me to do copy the array name values where I get all the Column index values from my SQLite database.
Hope anyone have an idea to do this.
Your post is quite hard to read, but I think the issue is that list1 has not been initialised.
You need to add a line like this:
list1 = new String[10];
before you attempt to set a value within the array.
ps - I picked a value of 10 as your for loop has i<10.