Android Studio: SQLite

MainActivity.java

package com.example.sairamkrishna.myapplication;

import android.content.Context;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;

import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends ActionBarActivity {
   public final static String EXTRA_MESSAGE = "MESSAGE";
   private ListView obj;
   DBHelper mydb;
   
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      
      mydb = new DBHelper(this);
      ArrayList array_list = mydb.getAllCotacts();
      ArrayAdapter arrayAdapter=new ArrayAdapter(this,android.R.layout.simple_list_item_1, array_list);
      
      obj = (ListView)findViewById(R.id.listView1);
      obj.setAdapter(arrayAdapter);
      obj.setOnItemClickListener(new OnItemClickListener(){
         @Override
         public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) {
            // TODO Auto-generated method stub
            int id_To_Search = arg2 + 1;
            
            Bundle dataBundle = new Bundle();
            dataBundle.putInt("id", id_To_Search);
            
            Intent intent = new Intent(getApplicationContext(),DisplayContact.class);
            
            intent.putExtras(dataBundle);
            startActivity(intent);
         }
      });
   }
    
   @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){
      super.onOptionsItemSelected(item);
      
      switch(item.getItemId()) {
         case R.id.item1:Bundle dataBundle = new Bundle();
         dataBundle.putInt("id", 0);
         
         Intent intent = new Intent(getApplicationContext(),DisplayContact.class);
         intent.putExtras(dataBundle);
         
         startActivity(intent);
         return true;
         default:
         return super.onOptionsItemSelected(item);
      }
   }
   
   public boolean onKeyDown(int keycode, KeyEvent event) {
      if (keycode == KeyEvent.KEYCODE_BACK) {
         moveTaskToBack(true);
      }
      return super.onKeyDown(keycode, event);
   }
} 

Referensi

• https://www.tutorialspoint.com/android/android_sqlite_database.htm