How to Create Button in Android Using This

activity_main.xml

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    tools:context=".MainActivity">



    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="Button"

        android:id="@+id/button"

        android:layout_gravity="center"

        android:layout_marginTop="45dp"

         />

</LinearLayout>



MainActivity.Java
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package com.anil.android.anilapp;



import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.Button;

import android.widget.Toast;



public class MainActivity extends AppCompatActivity  implements View.OnClickListener{

    Button b1;



    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        

        b1=(Button)findViewById(R.id.button);

        b1.setOnClickListener(this);

    }





    @Override

    public void onClick(View v) {

        Toast.makeText(getApplicationContext(),"Button is Working",Toast.LENGTH_LONG).show();

        

    }

}





Output 
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