Button Example1

Create new project, go to activity_main.xml drag and drop  a button or add the following code.

activity_main.xml

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

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

    android:id="@+id/LinearLayout1"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    tools:context=".MainActivity" >

    <Button

        android:id="@+id/click_button"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/button" />

</LinearLayout>

MainActivity.java

import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

Button b = (Button) findViewById(R.id.click_button);

b.setOnClickListener(this);

}

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

Toast.makeText(getApplicationContext(), "You have clicked on button",

Toast.LENGTH_SHORT).show();

}

}