Android中button兑现onclicklistener事件的两种方法

package com.demos;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class GetScreenActivity extends Activity {		private Button firstBtn = null;	private Button secBtn = null;		@Override	protected void onCreate(Bundle savedInstanceState) {				super.onCreate(savedInstanceState);		setContentView(R.layout.main);		firstBtn = (Button) findViewById(R.id.firstBtn);		secBtn = (Button) findViewById(R.id.secBtn);				firstBtn.setOnClickListener(listener);				secBtn.setOnClickListener(new OnClickListener() {			@Override			public void onClick(View v) {				// TODO Auto-generated method stub							}		});	}		private OnClickListener listener = new OnClickListener(){		@Override		public void onClick(View view) {					}			};	}