Mobile Application Development Practical 28
Question 1
Write a program to create the login form with necessary validations like length of username and password, empty text fields, count of unsuccessful login attempts. Display the login uccessful /Unsuccessful toastmessage.
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">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="30dp"
android:layout_marginRight="30dp"
android:layout_marginTop="50dp"
android:orientation="vertical">
<EditText
android:id="@+id/uname"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Enter Username" />
<EditText
android:id="@+id/pass"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:inputType="textPassword"
android:hint="Enter Password" />
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="30dp"
android:text="Login" />
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>MainActivity.java
package com.example.practical28;
import androidx.appcompat.app.AppCompatActivity;
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 uname, pass;
Button b;
int count=3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
uname = findViewById(R.id.uname);
pass = findViewById(R.id.pass);
b = findViewById(R.id.button);
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String username=uname.getText().toString();
String password=pass.getText().toString();
if(username.isEmpty()||password.isEmpty()) {
Toast.makeText(getApplicationContext(), "Username or password can not be blank", Toast.LENGTH_LONG).show();
}
else if (username.startsWith(" ")||password.startsWith(" ")) {
Toast.makeText(getApplicationContext(), "Username or password can not start with space", Toast.LENGTH_LONG).show();
}
else if(username.length()<5||password.length()<5){
Toast.makeText(getApplicationContext(),"Username or password is too short",Toast.LENGTH_LONG).show();
}
else if(username.equals("admin")&&password.equals("Admin123"))
Toast.makeText(getApplicationContext(),"Login successful",Toast.LENGTH_LONG).show();
else
{
count--;
if(count==0)
{
Toast.makeText(getApplicationContext(), "You have exceeded maximum number of login attempts", Toast.LENGTH_LONG).show();
b.setClickable(false);
uname.setEnabled(false);
pass.setEnabled(false);
}
else
Toast.makeText(getApplicationContext(),"Invalid login details\nYou have "+count+" attempts left",Toast.LENGTH_LONG).show();
}
}
});
}
}Output
