Activity中使用orientation属性讲解及需注意的问题

package com.example.activitypractice;

import android.app.Activity;
import android.content.Intent;
import android.content.res.Configuration;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {

	private static final String TAG = "MainActivity";
	

	//Activity创建时调用
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
	
		
		Log.i(TAG,"执行了onCreate方法");
	}
	
	//Activity创建或者从后台重新回到前台时被调用 
	@Override
	protected void onStart() {
		super.onStart();
		Log.i(TAG,"执行了onStart方法");
	}
	
	//Activity从后台重新回到前台时被调用
	@Override
	protected void onRestart() {
		super.onRestart();
		Log.i(TAG,"执行了onRestart方法");
	}
	
	//Activity创建或者从被覆盖、后台重新回到前台时被调用
	@Override
	protected void onResume() {
		super.onResume();
		Log.i(TAG,"执行了onResume方法");
	}
	
	//Activity被覆盖到下面或者锁屏时被调用  
	@Override
	protected void onPause() {
		super.onPause();
		Log.i(TAG,"执行了onPause方法");
	}
	
	//退出当前Activity或者跳转到新Activity时被调用  
	@Override
	protected void onStop() {
		super.onStop();
		Log.i(TAG,"执行了onStop方法");
	}
	
	//退出当前Activity时被调用,调用之后Activity就结束了  
	@Override
	protected void onDestroy() {
		super.onDestroy();
		Log.i(TAG,"执行了onDestroy方法");
	}
	//当指定了android:configChanges="orientation"后,方向改变时onConfigurationChanged被调用,并且activity不再销毁重建
	@Override
	public void onConfigurationChanged(Configuration newConfig) {
		super.onConfigurationChanged(newConfig);
		switch (newConfig.orientation) {
		case Configuration.ORIENTATION_PORTRAIT://竖屏
			Log.i(TAG,"竖屏");
			setContentView(R.layout.portrait);
			break;
		case Configuration.ORIENTATION_LANDSCAPE://横屏
			Log.i(TAG,"横屏");
			setContentView(R.layout.landscap);
		default:
			break;
		}
	}
}