Having followed several examples with no success, I find myself at a dead end on this issue. The issue I am encountering is how to fill a ListView with data from a database.
The purpose is to create a screen with the listView which displays only the name column from the database, then when the item is selected the application goes to a new screen where it displays the other data related to the item.
The things I’d like help with understanding are filling the ListView with data from just the “Name” column from my database table “Contacts” and then, getting the data from the row of the database based on the selected item.
Here is the code for the ContactsMenu class, where the names will be displayed.
package com.emailandcontactmanager;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;
public class ContactsMenu extends Activity {
ListView listView;
public static final String fields[] = { DatabaseSetup.colName};
Cursor cursor;
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.managecontacts);
listView = (ListView) findViewById(R.id.lstContacts);
DatabaseSetup.init(this);
Button btnAddItem = (Button) findViewById(R.id.btnAddContact);
btnAddItem.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent addItem = new Intent(v.getContext(), AddContact.class);
startActivity(addItem);
}
});
}
@Override
protected void onPause() {
listView.setAdapter(null);
cursor.close();
DatabaseSetup.deactivate();
super.onPause();
}
@Override
protected void onResume() {
super.onResume();
DatabaseSetup.init(this);
cursor = DatabaseSetup.getContactNames();
SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.row, cursor, fields, new int[] {R.id.item_text});
listView.setAdapter(adapter);
}
DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
switch (which){
case DialogInterface.BUTTON_POSITIVE:
finish();
break;
case DialogInterface.BUTTON_NEGATIVE:
//Nothing happens on No button click, and the menu closes
break;
}
}
};
@Override
public boolean onCreateOptionsMenu(Menu mainmenu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.mainmenu, mainmenu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
final CharSequence[] items = {"Contacts list", "Add Contact"};
switch (item.getItemId()) {
case R.id.help: AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Select a function to revice information about it.");
builder.setItems(items, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int selected) {
switch(selected){
case 0:
Toast.makeText(getApplicationContext(),
"Allows you to view the selected item and make editations to it or delete it.",
Toast.LENGTH_LONG).show();
break;
case 1:
Toast.makeText(getApplicationContext(),
"Allows you to add a new contact by bringing up a screen where the nececary information can be entered.",
Toast.LENGTH_LONG).show();
}
}
});
builder.show();
break;
case R.id.back: AlertDialog.Builder builderBack = new AlertDialog.Builder(this);
builderBack.setMessage("Are you sure?").setPositiveButton("Yes", dialogClickListener)
.setNegativeButton("No", dialogClickListener).show();
break;
}
return true;
}
}
Database Setup Class
package com.emailandcontactmanager;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
/*
* usage:
* DatabaseSetup.init(egActivityOrContext);
* DatabaseSetup.createEntry() or DatabaseSetup.getContactNames() or DatabaseSetup.getDb()
* DatabaseSetup.deactivate() then job done
*/
class DatabaseSetup extends SQLiteOpenHelper {
static DatabaseSetup instance = null;
static SQLiteDatabase db = null;
public static void init(Context context) {
if (null == instance) {
instance = new DatabaseSetup(context);
}
}
public static SQLiteDatabase getDb() {
if (null == db) {
db = instance.getWritableDatabase();
}
return db;
}
public static void deactivate() {
if (null != db && db.isOpen()) {
db.close();
}
db = null;
instance = null;
}
public static long createEntry(String name, String mail, String phone1,
String phone2, String address, String notes) {
ContentValues cv = new ContentValues();
cv.put(colName, name);
cv.put(colMail, mail);
cv.put(colPhone1, phone1);
cv.put(colPhone2, phone2);
cv.put(colAddress, address);
cv.put(colNotes, notes);
return getDb().insert(contactsTable, null, cv);
}
public static Cursor getContactNames() {
// TODO Auto-generated method stub
String[] columns = new String[] {"_id", colName };
return getDb().query(contactsTable, columns, null, null, null, null,
null);
}
DatabaseSetup(Context context) {
super(context, dbName, null, dbVersion);
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL("CREATE TABLE IF NOT EXISTS " + contactsTable
+ " (_id integer primary key autoincrement, " + colName
+ " TEXT NOT NULL, " + colMail + " TEXT NOT NULL, " + colPhone1
+ " TEXT NOT NULL, " + colPhone2 + " TEXT NOT NULL, "
+ colAddress + " TEXT NOT NULL, " + colNotes
+ " TEXT NOT NULL)");
db.execSQL("CREATE TABLE IF NOT EXISTS " + templatesTable
+ " (_id integer primary key autoincrement, " + colSubject
+ " TEXT NOT NULL, " + colBody + " TEXT NOT NULL)");
db.execSQL("CREATE TABLE IF NOT EXISTS " + tagsTable
+ " (_id integer primary key autoincrement, " + colTagName
+ " TEXT NOT NULL, " + colContact + " TEXT NOT NULL)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + contactsTable);
db.execSQL("DROP TABLE IF EXISTS " + templatesTable);
db.execSQL("DROP TABLE IF EXISTS " + tagsTable);
onCreate(db);
}
static final String dbName = "DB";
static final int dbVersion = 1;
static final String contactsTable = "Contacts";
static final String colName = "Name";
static final String colMail = "Email";
static final String colPhone1 = "Phone1";
static final String colPhone2 = "Phone2";
static final String colAddress = "Address";
static final String colNotes = "Notes";
static final String templatesTable = "Templates";
static final String colSubject = "Subject";
static final String colBody = "Body";
static final String tagsTable = "Tags";
static final String colTagName = "Name";
static final String colContact = "Contact";
}
The code for the class to add to the contact menu. It used to work when I had a temporary display, however, now it does not.
package com.emailandcontactmanager;
import android.app.Activity;
import android.app.Dialog;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class AddContact extends Activity
{
Button saveContact;
EditText contactName, contactMail, contactPhone1, contactPhone2, contactAddress, contactNotes;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.newcontact);
contactName = (EditText) findViewById(R.id.txtName);
contactMail = (EditText) findViewById(R.id.txtMail);
contactPhone1 = (EditText) findViewById(R.id.txtPhone1);
contactPhone2 = (EditText) findViewById(R.id.txtPhone2);
contactAddress = (EditText) findViewById(R.id.txtAddress);
contactNotes = (EditText) findViewById(R.id.txtNotes);
// saveContact = (Button) findViewById(R.id.btnSaveContact);
Button btnSaveContact = (Button) findViewById(R.id.btnSaveContact);
btnSaveContact.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
boolean working = true;
try{
String name = contactName.getText().toString();
String mail = contactMail.getText().toString();
String phone1 = contactPhone1.getText().toString();
String phone2 = contactPhone2.getText().toString();
String address = contactAddress.getText().toString();
String notes = contactNotes.getText().toString();
DatabaseSetup entry = new DatabaseSetup(AddContact.this);
DatabaseSetup.getDb();
DatabaseSetup.createEntry(name, mail, phone1, phone2, address, notes);
entry.close();
}
catch(Exception e)
{
working = false;
String error = e.toString();
Dialog d = new Dialog(AddContact.this);
d.setTitle("Error");
TextView tv = new TextView(AddContact.this);
tv.setText(error);
}
finally
{
if(working)
{
Dialog d = new Dialog(AddContact.this);
d.setTitle("Success");
TextView tv = new TextView(AddContact.this);
tv.setText("The database changes have succeeded.");
d.setContentView(tv);
d.show();
}
}
}
});
}
}
Here is Activity sample code:
Here is DatabaseSetup sample code:
Here is ‘res/layout/row.xml’
Hope it helps.