标签:ar os 使用 java sp on bs as new
假设有这样一个场景,app第一个页面是一个正方形,第二个页面有一个按钮,点击第一个的某按钮后,跳转到第二个页面,第二个页面修改正方形的边长,然后返回第一个页面,此时当前页面的矩形变化。
import java.util.Objects; /** * Created by itfanr on 14/11/11. */ public interface ClickDelegate { public void lengthDidChange(SecondPage sp , int length) ; }
/** * Created by itfanr on 14/11/11. */ public class FirstPage implements ClickDelegate { private int area ; @Override public void lengthDidChange(SecondPage sp, int length) { this.area = length *2 ; System.out.println("back to first page"); System.out.println("area is also changed : " + this.area+ "\n"); } public SecondPage jumpToSecond(){ System.out.println("jump to second page"); SecondPage sp = new SecondPage() ; sp.cd = this ; return sp ; } }
/** * Created by itfanr on 14/11/11. */ public class SecondPage { private int length = 10; public ClickDelegate cd = null ; public void click() { System.out.println("clicked in second page !"); this.length++; if (this.cd != null) { System.out.println("length is " + this.length); this.cd.lengthDidChange(this, this.length) ; } } }
/** * Created by itfanr on 14/11/11. */ public class Client { public static void main(String args[]){ FirstPage fp = new FirstPage() ; SecondPage sp = fp.jumpToSecond(); sp.click(); sp.click(); } }
输出结果如下:
jump to second page clicked in second page ! length is 11 back to first page area is also changed : 22 clicked in second page ! length is 12 back to first page area is also changed : 24
感觉和普通的观察者模式有点不同。如果是普通的观察者模式,应该是第二个页面观察第一个页面的变化。
标签:ar os 使用 java sp on bs as new
原文地址:http://my.oschina.net/itfanr/blog/343212