Android Learning Course - part 4

java part : 

package first.learn.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {


 void showMyName (String name){
     Toast.makeText(this, name, Toast.LENGTH_LONG).show();
     txtOne.setText(name);
 }

 void  addTwoNumbers (int a, int b ){
        int c = a+b;

     Toast.makeText(this, ""+c, Toast.LENGTH_SHORT).show();
     txtTwo.setText(""+c );

 }

    TextView txtOne, txtTwo ;
    Button btnOne, btntwo ;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        txtOne = (TextView) findViewById(R.id.txtOne);
        txtTwo = (TextView) findViewById(R.id.txtTwo);
        btnOne = (Button)findViewById(R.id.btnOne);
        btntwo = (Button)findViewById(R.id.btntwo);

        txtOne.setText("Alhamdulillah");


        showMyName("Ahsanul Islam");


        addTwoNumbers(12,10);

        txtTwo.setText(" this is my test");

        btnOne.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                addTwoNumbers(50, 55);

            }
        });

        btntwo.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                showMyName("Ahsan\n\nRuhul Amin\n\nAbu Bakr\n\nMahmudul Hasan");
            }
        });







    }


}

xml part : 

<?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"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <TextView
        android:layout_margin="20dp"
        android:id="@+id/txtOne"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Bismillahir Rahmanir Rahim!"

        />

    <TextView
        android:layout_margin="20dp"
        android:id="@+id/txtTwo"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Bismillahir Rahmanir Rahim!"

        />


    <Button
        android:layout_margin="20dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Button One "
        android:id="@+id/btnOne"/>

    <Button
        android:layout_margin="20dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Button two "
        android:id="@+id/btntwo"/>

</LinearLayout>