android 札记 - Android中Menu应用

android 笔记 --- Android中Menu应用
Android menu是Android开发中经常使用的，下面的例子是Menu使用的简单示例：

package com.enjoy.menu;
 
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
 
public class SystemMenu extends Activity {
	public static final int SAVE = Menu.FIRST;
	public static final int RETURN_MENU = Menu.FIRST+1;
	public static final int QUIT = Menu.FIRST+2;
    @Override
    public void onCreate(Bundle savedInstanceState) {
 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		menu.add(0,SAVE,0,"保存");
		menu.add(0,RETURN_MENU,1,"返回主菜单");
		menu.add(0,QUIT,2,"退出");
		return super.onCreateOptionsMenu(menu);
 
	}
	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		TextView tv = (TextView)findViewById(R.id.tv01);
		switch(item.getItemId()){
			case SAVE:tv.setText("保存按钮被点击");break;
			case RETURN_MENU:tv.setText("返回主菜单按钮被点击");break;
			case QUIT:tv.setText("退出按钮被点击");break;
		}
		return super.onOptionsItemSelected(item);
	}
 
 
}