Button setOnClickListener Example

Hello,

This article is for Beginner and people who want to learn Android .This article is about learn Button setOnClickListener . when we clicked on button it shows Toast Message.

1. XML File .

activity_main -

<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:orientation="vertical"  

 android:layout_height="match_parent" 

 tools:context=".MainActivity">

<Button    

android:id="@+id/btn"

android:text="Button"    

android:layout_width="match_parent"    

android:layout_height="wrap_content" />

</LinearLayout>

2.Java File

MainActivity -
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
//declare variable    Button btn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
         
   btn=findViewById(R.id.btn);
        //add setonclick listener       
 btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //show message on button click listener     
           Toast.makeText(MainActivity.this,"Hey",Toast.LENGTH_SHORT).show();
            }
        });


    }
}