接上一篇文章，这次我们来讲一下策略模式，什么是策略模式呢？这里我们还是拿《西游记》来打比方，唐僧被抓走了，就会叫人来救，但谁去救呢？当然是唐僧叫谁去救，谁就去救啦，呵呵，但一般最后都是悟空救出来的。好，让我们先来看一下UML例图：
首先抽象了救人的方法，因为每个人救的方法都不同，而唐僧只要叫人救他就行了，他不管你具体怎么去救，好，我们接下来看代码:
[
java] public
interface Person {
public String save();
}
public interface Person {
public String save();
}这是抽象方法，每个具体类都要去实现这个方法
接下来就是具体类了，首先是悟空
[
java] public class Wukong implements Person {
@Override
public String save() {
return "大徒弟孙悟空来救师傅";
}
}
public class Wukong implements Person {
@Override
public String save() {
return "大徒弟孙悟空来救师傅";
}
}接下来是八戒
[
java] public class Bajie implements Person {
@Override
public String save() {
return "二徒弟猪八戒来救师傅";
}
}
public class Bajie implements Person {
@Override
public String save() {
return "二徒弟猪八戒来救师傅";
}
}最后就是沙僧
[
java] public class Shaseng implements Person {
@Override
public String save() {
return "三徒弟沙僧来救师傅";
}
}
public class Shaseng implements Person {
@Override
public String save() {
return "三徒弟沙僧来救师傅";
}
}好了，三个具体类都完成了救人的方法，接下去就是唐僧了
[
java] public class Tangseng {
public String help(Person p) {
return p.save();
}
}
public class Tangseng {
public String help(Person p) {
return p.save();
}
}
唐僧会喊悟空，八戒，沙僧来救我，那听到的就会去救他，呵呵，最后就是
Android中的实现了
[
java] public class XiyoujiActivity extends Activity {
private ListView listView;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
listView = (ListView) findViewById(R.id.listView1);
Tangseng tangseng = new Tangseng();
ArrayList<String> lists = new ArrayList<String>();
lists.add(tangseng.help(new Wukong()));
lists.add(tangseng.help(new Bajie()));
lists.add(tangseng.help(new Shaseng()));
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
Android.R.layout.simple_list_item_1, lists);
listView.setAdapter(adapter);
}
}
public class XiyoujiActivity extends Activity {
private ListView listView;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
listView = (ListView) findViewById(R.id.listView1);
Tangseng tangseng = new Tangseng();
ArrayList<String> lists = new ArrayList<String>();
lists.add(tangseng.help(new Wukong()));
lists.add(tangseng.help(new Bajie()));
lists.add(tangseng.help(new Shaseng()));
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
Android.R.layout.simple_list_item_1, lists);
listView.setAdapter(adapter);
}
}这里面的界面也只加了个ListView，相信同学们应该都能看懂，最后就是运行过后的图了：
好了，这一章也写完了，谢谢
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