广播的注册和解除注册

package com.gyarmy.lockScreen;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.content.IntentFilter;
import android.view.Menu;

public class MainActivity extends Activity {

	private ScreenActivity phoneScreen;
	
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        phoneScreen = new ScreenActivity();
        IntentFilter filter = new IntentFilter();
        //intent.setAction("android.intent.action.SCREEN_OFF");
        //intent.setAction("android.intent.action.SCREEN_ON");
        filter.addAction("android.intent.action.SCREEN_OFF");
        filter.addAction("android.intent.action.SCREEN_ON");
        
        registerReceiver(phoneScreen, filter);
        
        
    }
    
    @Override
    protected void onDestroy() {
    	// TODO Auto-generated method stub
    	super.onDestroy();
    	
    	unregisterReceiver(phoneScreen);
    }


}