2. To understand Activity, Intent
i. Create sample application with login module.(Check username and
password)
ii. On successful login, go to next screen. And on failing login, alert user using
Toast.
iii. Also pass username to next screen.


MainActivity.java

package com.example.assignment2;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;

import android.os.Bundle;

import android.text.TextUtils;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    EditText username,password;

    Button btnLogin;

    String correct_username = "HGC";

    String correct_password = "123";

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        username = findViewById(R.id.username);

        password = findViewById(R.id.password);

        btnLogin = findViewById(R.id.button);

        btnLogin.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                if (TextUtils.isEmpty(username.getText().toString()) || TextUtils.isEmpty(password.getText().toString())) {

                    Toast.makeText(MainActivity.this, "Empty Data Provided", Toast.LENGTH_LONG).show();

                } else if (username.getText().toString().equals(correct_username)) {

                    if (password.getText().toString().equals(correct_password)) {

                       Intent intent = new Intent(MainActivity.this, SecondActivity.class);

                       startActivity(intent);

                    } else {

                        Toast.makeText(MainActivity.this, "Invalid Username/Password", Toast.LENGTH_LONG).show();

                    }

                } else {

                    Toast.makeText(MainActivity.this, "Invalid Username/Passsword", Toast.LENGTH_LONG).show();

                }

            }

        });

    }

}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

<androidx.constraintlayout.widget.ConstraintLayout 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=".MainActivity">

    <EditText

        android:id="@+id/username"

        android:layout_width="214dp"

        android:layout_height="0dp"

        android:layout_marginTop="268dp"

        android:ems="10"

        android:hint="Username"

        android:inputType="textPersonName"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintHorizontal_bias="0.502"

        app:layout_constraintStart_toStartOf="parent"

        app:layout_constraintTop_toTopOf="parent" />

    <EditText

        android:id="@+id/password"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_marginTop="44dp"

        android:ems="10"

        android:hint="Password"

        android:inputType="textPassword"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintStart_toStartOf="parent"

        app:layout_constraintTop_toBottomOf="@+id/username" />

    <Button

        android:id="@+id/button"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="Login"

        app:layout_constraintBottom_toBottomOf="parent"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintHorizontal_bias="0.52"

        app:layout_constraintStart_toStartOf="parent"

        app:layout_constraintTop_toTopOf="parent"

        app:layout_constraintVertical_bias="0.699" />

    <TextView

        android:id="@+id/textView2"

        android:layout_width="94dp"

        android:layout_height="39dp"

        android:text="LOGIN"

        android:textColor="#050505"

        android:textSize="24sp"

        app:layout_constraintBottom_toBottomOf="parent"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintHorizontal_bias="0.511"

        app:layout_constraintStart_toStartOf="parent"

        app:layout_constraintTop_toTopOf="parent"

        app:layout_constraintVertical_bias="0.193" />

</androidx.constraintlayout.widget.ConstraintLayout>

SecondActivity.java

package com.example.assignment2;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

public class SecondActivity extends AppCompatActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_second);

    }

}

activity_second.xml

<?xml version="1.0" encoding="utf-8"?>

<androidx.constraintlayout.widget.ConstraintLayout 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=".SecondActivity">

    <TextView

        android:layout_width="82dp"

        android:layout_height="61dp"

        android:text="HGC"

        android:textColor="#040303"

        android:textSize="30sp"

        app:layout_constraintBottom_toBottomOf="parent"

        app:layout_constraintHorizontal_bias="0.553"

        app:layout_constraintLeft_toLeftOf="parent"

        app:layout_constraintRight_toRightOf="parent"

        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>




Output

The username is HGC and the password is 123
To download follow this link : Program 2