Delete a record from a ListView–Android database SQLite (p8)

This tutorial is the continuation of the tutorial in Add new Record

By long-pressing a record, user will invoke the Dialog box. Choose DELETE to confirm deleting the selected record. Choosing UPDATE will invoke the update record screen.

Download the complete code here  http://khirulnizam.com/android/FSTMDirektori.zip

STEP 1: Adjusting the onItemLongClickListener to accommodate the deleting a record facilities.

The updated DisplayList.java with the delete record function

package net.kerul.fstmdirektori;

import java.util.ArrayList;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemLongClickListener;
import android.widget.ListView;
import android.widget.Toast;

public class DisplayList extends Activity {
    
    private String id;//to hold selected stafid 
    private DBHelper mHelper;
    private SQLiteDatabase dataBase;

    //variables to hold staff records
    private ArrayList<String> stafid = new ArrayList<String>();
    private ArrayList<String> nama = new ArrayList<String>();
    private ArrayList<String> jbt = new ArrayList<String>();

    private ListView userList;
    private AlertDialog.Builder build;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_display_list);

        userList = (ListView) findViewById(R.id.List);

        mHelper = new DBHelper(this);
        
        //click to update data
        userList.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                    long arg3) {

                Intent i = new Intent(getApplicationContext(),
                        ViewRecord.class);
                i.putExtra("stafid", stafid.get(arg2));
                startActivity(i);
            }
        });//end setOnItemClickListener
        
        //long-press to update data
        userList.setOnItemLongClickListener(new OnItemLongClickListener() {

            public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
                    final int arg2, long arg3) {
                
                //invoking AlertDialog box
                build = new AlertDialog.Builder(DisplayList.this);
                build.setTitle("Update/Delete staff " + nama.get(arg2));
                build.setMessage("Do you want to update/delete the record?(Hit back to cancel)");
                
                //user select UPDATE
                build.setNegativeButton("UPDATE",
                    new DialogInterface.OnClickListener() {

                        public void onClick(DialogInterface dialog,
                                int which) {
                            //Update record selected
                            Intent i = new Intent(getApplicationContext(),
                                    UpdateRecord.class);
                            i.putExtra("stafid", stafid.get(arg2));
                            startActivity(i);
                            dialog.cancel();
                        }
                    });//end UPDATE
                
                //user select DELETE
                build.setPositiveButton("DELETE",
                        new DialogInterface.OnClickListener() {

                            public void onClick(DialogInterface dialog,int which) {
                                dataBase.delete(
                                        DBHelper.TABLE_NAME,
                                        DBHelper.STAFID + "="
                                                + stafid.get(arg2), null);
                                Toast.makeText(
                                        getApplicationContext(),
                                        nama.get(arg2)+
                                        " is deleted.", Toast.LENGTH_SHORT).show();
                                displayData();
                                dialog.cancel();
                            }
                        });//end DELETE
                AlertDialog alert = build.create();
                alert.show();

                return true;
            }
        });//end setOnItemLongClickListener
        
        
    }// end onCreate method

    @Override
    protected void onResume() {
        //refresh data for screen is invoked/displayed
        displayData();
        Toast.makeText(getApplicationContext(), "TAP to view complete info, \n LONG-TAP to update/delete...", Toast.LENGTH_LONG).show();
        super.onResume();
    }

    /**
     * displays data from SQLite
     */
    private void displayData() {
        dataBase = mHelper.getWritableDatabase();
        //the SQL command to fetched all records from the table
        Cursor mCursor = dataBase.rawQuery("SELECT * FROM "
                + DBHelper.TABLE_NAME, null);

        //reset variables
        stafid.clear();
        nama.clear();
        jbt.clear();
        
        //fetch each record
        if (mCursor.moveToFirst()) {
            do {
                //get data from field 
                stafid.add(mCursor.getString(mCursor.getColumnIndex(DBHelper.STAFID)));
                nama.add(mCursor.getString(mCursor.getColumnIndex(DBHelper.NAMA)));
                jbt.add(mCursor.getString(mCursor.getColumnIndex(DBHelper.JBT)));
                
            } while (mCursor.moveToNext());
            //do above till data exhausted 
        }
        
        //display to screen
        DisplayAdapter disadpt = new DisplayAdapter(DisplayList.this, stafid, nama, jbt);
        userList.setAdapter(disadpt);
        mCursor.close();
    }//end displayData
    
    


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.display_list, menu);
        return true;
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle item selection
        if (item.getItemId()==R.id.m_add_record) {
            
            //invoke the AddNewRecord screen using Intent
            Intent i = new Intent(getApplicationContext(),
                    AddNewRecord.class);
            startActivity(i);
        }
        return true;
    }
    
}//end DisplayList class