兄弟连云Android 学习笔记—菜单

菜单：

       1.Options menu and action bar 选项菜单

      2.Context menu   上下文菜单

      3.Popup menu    弹出式菜单

1.Options menu and action bar 选项菜单

创建选项菜单步骤：

1.覆盖Activity 的onCreateOptionMenu(Menu menu)方法，当菜单第一次被打开时调用

2.调用Menu的add()方法添加菜单项（MenuItem）,同时可以调用MenuItem的setIcon()方法来为菜单项设置图标

3.当菜单项（MenuItem）被选择时，覆盖Activity的onOptionsItemSelected(MenuItem  item)来响应事件action bar         

***资源文件名必须全用小写，可以用下划线隔开，不能数字开头      

MainActivity.java

package com.example.hello;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.widget.Toast;


public class MainActivity extends Activity {

	private static final int START_ITEM = Menu.FIRST;
	private static final int OVER_ITEM = Menu.FIRST + 1;
	private static final int SET_ITEM1 = Menu.FIRST + 2;
	private static final int SET_ITEM2 = Menu.FIRST + 3;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
	}

	//重写onCreateOptionsMenu方法
	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		// getMenuInflater().inflate(R.menu.main, menu);
		// 添加菜单项（组id,菜单id,排序，标题）
		menu.add(0, START_ITEM, 100, "开始");
		menu.add(0, OVER_ITEM, 200, "结束");
		// 添加子菜单
		SubMenu sub1 = menu.addSubMenu("设置");
		sub1.add(1, SET_ITEM1, 300, "设置声音");
		sub1.add(1, SET_ITEM2, 300, "设置桌面");
		System.out.println("onCreateOptionsMenu...");
		return true;

	}

	// 重写onOptionItemSelected方法实现菜单选项事件
	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		// TODO Auto-generated method stub
		System.out.println("onOptionsItemSelected...");
		switch (item.getItemId()) {
		case START_ITEM:
			// R.id.start:
			// 弹框，提示信息
			Toast.makeText(this, "开始游戏", Toast.LENGTH_SHORT).show();
			break;
		case OVER_ITEM:
			// R.id.over:
			Toast.makeText(this, "结束游戏", Toast.LENGTH_SHORT).show();
			break;
		case SET_ITEM1:
			// R.id.over:
			Toast.makeText(this, "设置声音", Toast.LENGTH_SHORT).show();
			break;
		case SET_ITEM2:
			// R.id.over:
			Toast.makeText(this, "设置桌面", Toast.LENGTH_SHORT).show();
			break;
		default:
			break;
		}
		return super.onOptionsItemSelected(item);
	}
}

2..Context menu   上下文菜单

1.覆盖Activity 的onCreateContextMenu(Menu menu)方法，调用Menu的add（）方法添加菜单项（MenuItem）

2.覆盖Activity的onCreatetextItem Selected(Menu menu)来响应事件

3.调用registerForContextMenu()方法为视图注册上下文菜单

mainActivity2.java

package com.example.hello;

import android.app.Activity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.View;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.Button;
import android.widget.Toast;

//上下文菜单
public class MainActivity2 extends Activity {

	private Button btn1;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main2);
		// 获取BUTTON对象
		btn1 = (Button) findViewById(R.id.button1);
		//在button上注册上下文菜单
		registerForContextMenu(btn1);
	}

	// 创建上下文菜单的方法
	@Override
	public void onCreateContextMenu(ContextMenu menu, View v,
			ContextMenuInfo menuInfo) {
		// TODO Auto-generated method stub
		super.onCreateContextMenu(menu, v, menuInfo);
		getMenuInflater().inflate(R.menu.main2, menu);
	}

	// 上下文触发事件
	@Override
	public boolean onContextItemSelected(MenuItem item) {
		switch (item.getItemId()) {
		case R.id.start:
			Toast.makeText(this, "开始",Toast.LENGTH_SHORT).show();
			break;
		case R.id.over:
			Toast.makeText(this, "结束",Toast.LENGTH_SHORT).show();
			break;
		default:
			break;
		}
		return super.onContextItemSelected(item);
	}
}

  3.Popup menu    弹出式菜单

弹出式菜单是在API 11级或更高级才有效

mainActivity3.java

package com.example.hello;

import android.app.Activity;
import android.os.Bundle;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.PopupMenu;
import android.widget.Toast;

public class mainActivity3 extends Activity implements android.widget.PopupMenu.OnMenuItemClickListener {
	private Button btn1;
	//弹出式菜单
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main3);
	}
	
	public void showPopupMenu(View v){
		//创建弹出式菜单对象
		PopupMenu popup = new PopupMenu(this,v);
		MenuInflater inflater = popup.getMenuInflater();
		inflater.inflate(R.menu.main3,popup.getMenu());
		//设置菜单项的单击事件
		popup.setOnMenuItemClickListener(this);
		popup.show();
	}

	@Override
	public boolean onMenuItemClick(MenuItem item) {
		switch (item.getItemId()) {
		case R.id.copy:
			Toast.makeText(this, "复制", Toast.LENGTH_LONG).show();
			break;
		case R.id.del:
			Toast.makeText(this, "删除", Toast.LENGTH_LONG).show();
			break;
		default:
			break;
		}
		return false;
	}
	
}