findViewById

package com.example.test_0926;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity implements OnClickListener{

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        Button btnOK = (Button)findViewById(R.id.btnOK);
        Button btnCancel = (Button)findViewById(R.id.btnCancel);
        
        btnOK.setOnClickListener(this);
        btnCancel.setOnClickListener(this);        
    
    }

    
    public void onClick(View v){
     switch(v.getId()){
      case R.id.btnOK:
       Log.i("MyTag","OK >>");
       break;
      case R.id.btnCancel:
       Log.i("MyTag","Cancel >>");
       break;
     }
    }
    
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
}