Getting started with Android-Hello World

package my.hello.world;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class HelloWorldActivity extends Activity {
    /** Called when the activity is first created. */
    Button hello;
    TextView txt;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
       
        hello=(Button) findViewById(R.id.hello);
        txt=(TextView) findViewById(R.id.txt);
       
        hello.setOnClickListener(new OnClickListener() {
           
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
           
                txt.setText("Hello world");
               
            }
        });
             
     }
}



In above example we see that we used one TextView and one Button.
On the Button onclicklistener activity we simply set the Text as "Hello World" .