Android app main activity Async Task

Hi Friend's recently i have created android application for election management(Voter search and other statics and reports as well as Messaging voter details).

I have developed this application for one of my client , Application requirement was storing almost 3 To 4 Lakh Record's in local phone memory without using internet and this was biggest challenge  for bcz I have not studied android and this was my first app in android .

I'm Posting some codes which may help you ............


 MainActivity.java
This is my main activity code  which create Database and do AsynTask like showing progress bar.........


package com.example.rajmal.dummy;


import java.io.IOException;

import android.os.AsyncTask;
import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.view.View.OnClickListener;
import android.database.sqlite.SQLiteDatabase;


@SuppressLint({ "ParserError", "ParserError" })
public class mainactivity extends Activity implements OnClickListener  {
protected Button btnmarathi;
protected Button btnenglish;
protected Button btnSendMessage;
Context context;
private int mProgressStatus = 0;
private ProgressDialog mProgressDialog ;
private ProgressBarAsync mProgressbarAsync;
protected SQLiteDatabase db,db1,db2,db3,db4,db5,db6;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mainmarathi);
      //  setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        mProgressDialog = new ProgressDialog(this);
       
        /** Close the dialog window on pressing back button */
        mProgressDialog.setCancelable(false);

        /** Setting a horizontal style progress bar */
        mProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);

        /** Setting a message for this progress dialog
        * Use the method setTitle(), for setting a title
        * for the dialog window
        *  */
        mProgressDialog.setMessage("Initializing Database .....");
        mProgressDialog.show();
       
        /** Creating an instance of ProgressBarAsync */
        mProgressbarAsync = new ProgressBarAsync();

        /** ProgressBar starts its execution */
        mProgressbarAsync.execute();
       
     
   
       btnmarathi = (Button) findViewById(R.id.btnmarathi);
       btnenglish = (Button) findViewById(R.id.btnEnglish);
       btnSendMessage=(Button)findViewById(R.id.btnsendmsg);

       
    }
  public void CreateDb()
  {
 db = (new DatabaseHelper(this)).getWritableDatabase();
      db1 = (new DatabaseHelper1(this)).getWritableDatabase();
     db2 = (new DatabaseHelper2(this)).getWritableDatabase();
      db3 = (new DatabaseHelper3(this)).getWritableDatabase();
      db4 = (new DatabaseHelper4(this)).getWritableDatabase();
      db5 = (new DatabaseHelper5(this)).getWritableDatabase();
      db6 = (new DatabaseHelper6(this)).getWritableDatabase();
  }
public void handleClick(View v){
       
        //Create an intent to start the new activity.
           // Our intention is to start secondActivity
    switch(v.getId())
    {
    case R.id.btnmarathi:
        Intent intent = new Intent();
        intent.setClass(this,Menuclick.class);
       // db2 = (new DatabaseHelper2(this)).getWritableDatabase();
        startActivity(intent);
    break;
       case R.id.btnEnglish:
    Intent intent1 = new Intent();
           intent1.setClass(this,Menuclick.class);
        //   db3 = (new DatabaseHelper3(this)).getWritableDatabase();
           startActivity(intent1);
           break;
       case R.id.btnsendmsg:
    Intent intent2 = new Intent();
           intent2.setClass(this,SendSMSActivity.class);
           startActivity(intent2);
           break;
   
    }
       }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.layout.mainmarathi, menu);
        return true;
    }

@Override
public void onClick(View v) {
//  Intent myintent = new Intent(mainactivity.this, EmployeeList.class);
  // startActivity(myintent);
}

   

private class ProgressBarAsync extends AsyncTask<Void, Integer, Void>{

    /** This callback method is invoked, before starting the background process */
    @Override
        protected void onPreExecute() {
   
        super.onPreExecute();
       // mProgressStatus = 0;
    }

    /** This callback method is invoked on calling execute() method
    * on an instance of this class */
    @Override
    protected Void doInBackground(Void...params) {
    CreateDb();
return null;
     
        //return null;
    }

    /** This callback method is invoked when publishProgress()
    * method is called */
 
   /* protected void onProgressUpdate(Integer... values) {
        super.onProgressUpdate(values);
        mProgressDialog.setProgress(mProgressStatus);
    }*/

    /** This callback method is invoked when the background function
    * doInBackground() is executed completely */
    @Override
    protected void onPostExecute(Void result) {
        super.onPostExecute(result);
        mProgressDialog.dismiss();
    }
}
}