Programming Examples

Android app to demonstrate the list view

Android application to Show data on ListView from SQLiIte Database

Output

main_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center"
    tools:context=".MainActivity">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:text="Student Name"/>
    <EditText
        android:id="@+id/stu_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="textPersonName"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="5dp"
         />
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="15dp"
        android:text="Mobile No."/>
    <EditText
        android:id="@+id/stu_mobile"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="5dp"
        android:inputType="textPersonName"
        />
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="15dp"
        android:text="Email ID"/>
    <EditText
        android:id="@+id/stu_email"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="5dp"
        android:inputType="textPersonName"
       />
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_marginTop="20dp"
        android:gravity="center">
        <Button
            android:id="@+id/btn_save"
            android:layout_width="120dp"
            android:layout_height="60dp"
            android:text="SAVE"/>
        <Button
            android:id="@+id/btn_view"
            android:layout_width="120dp"
            android:layout_height="60dp"
            android:layout_marginLeft="20dp"
            android:text="VIEW"/>
    </LinearLayout>

</LinearLayout>

MainActivity.java

package com.example.dbconnection;

import androidx.appcompat.app.ActionBar;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    EditText t1,t2,t3;
    Button b1,b2;
    dbHelper DB;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ActionBar actionBar=getSupportActionBar();
        actionBar.setTitle("Add Student");
        t1=findViewById(R.id.stu_name);
        t2=findViewById(R.id.stu_mobile);
        t3=findViewById(R.id.stu_email);
        b1=findViewById(R.id.btn_save);
        b2=findViewById(R.id.btn_view);
        b3=findViewById(R.id.btn_view_all);
        DB=new dbHelper(this);
        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String name=t1.getText().toString();
                String mobile=t2.getText().toString();
                String email=t3.getText().toString();
                Boolean chkIns=DB.insertData(name,mobile,email);
                if(chkIns==true)
                {
                    Toast.makeText(MainActivity.this,"Data Saved Successfully",Toast.LENGTH_SHORT).show();
                }
                else
                {
                    Toast.makeText(MainActivity.this,"Some Error in Insert data",Toast.LENGTH_SHORT).show();
                }
            }
        });

        b2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(MainActivity.this,StudentList.class);
                startActivity(intent);
            }
        });
    }
}

dbHelper.java

package com.example.dbconnection;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import androidx.annotation.Nullable;

public class dbHelper extends SQLiteOpenHelper {
    public dbHelper(@Nullable Context context) {
        super(context, "stu.db", null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
db.execSQL("create Table Userdetails(name TEXT primary key,mobile TEXT,email TEXT)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("drop Table if exists Userdetails");
    }
    public Boolean insertData(String name,String mobile,String email)
    {
        SQLiteDatabase db=this.getWritableDatabase();
        ContentValues contentValues=new ContentValues();
        contentValues.put("name",name);
        contentValues.put("mobile",mobile);
        contentValues.put("email",email);
        long result=db.insert("Userdetails",null,contentValues);
        if(result==-1)
        {
            return false;
        }
        else
        {
            return true;
        }
    }

    public Cursor getData()
    {
        SQLiteDatabase db=this.getWritableDatabase();
        Cursor cursor=db.rawQuery("select * from Userdetails",null);
        return cursor;
    }
}

activity_student_list.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".StudentList">

    <ListView
        android:id="@+id/stu_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</RelativeLayout>

StudentList.java

package com.example.dbconnection;

import androidx.appcompat.app.ActionBar;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;

public class StudentList extends AppCompatActivity {

    private dbHelper DB;
    private ListView listView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_student_list);
        ActionBar actionBar=getSupportActionBar();
        actionBar.setTitle("Student List");
        DB=new dbHelper(this);
        listView=findViewById(R.id.stu_list);

        Cursor res=DB.getData();
        ArrayList<String> arrayList=new ArrayList<>();
        //StringBuffer buffer=new StringBuffer();
        while(res.moveToNext()){

            arrayList.add("+"+res.getString(0)+"\n"+res.getString(1));
            //buffer.append("Name : "+res.getString(0)+"\t");
            //buffer.append("Mobile : "+res.getString(1)+"\t");
           // buffer.append("Email : "+res.getString(2)+"\n");
        }
        ArrayAdapter arrayAdapter=new ArrayAdapter(this, android.R.layout.simple_list_item_1,arrayList);
        listView.setAdapter(arrayAdapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //Toast.makeText(StudentList.this,"Clicked Item"+position+" "+arrayList.get(position).toString(),Toast.LENGTH_LONG).show();
                Intent intent=new Intent(StudentList.this,StudentProfile.class);
                intent.putExtra("NAME","dkm");
                startActivity(intent);
            }
        });

    }
}