Android应用开发UI（菜单）

Android手机有一个"Menu"键，用来专门显示菜单，要实现菜单功能，需要通过onCreateOptionsMenu（）来创建菜单，然后需要对其能够触发的事件进行监听，这样才能够在事件监听onOptionsItemSelected中根据不同的菜单选项来执行不同的任务。

添加菜单日有两种方式，一种是XAL布局，另一种是通过Menu.add()方法添加。

第一种，通过XML布局，在res下创建menu目录，在里面添加menu.xml文件，内容：

<?xml version="1.0" encoding="utf-8"?>
<menu
  xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:title="@string/about" android:id="@+id/about">
    </item>
    <item android:title="@string/exit" android:id="@+id/exit">
    </item>
</menu>

 

第二种，Menu.add（0，0，0，R.string.btn_name）方示添加：

@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		menu.add(0,0,0,R.string.ok);
		menu.add(0,0,0,R.string.back);
		return true;
	}

 

效果图：

 

 

 

代码：

1.res/values/string.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="about_me">详细内容可登录http://www.80080088.com了解!</string>
    <string name="main_menu">这里演示的是Andrid菜单功能!</string>
    <string name="app_name">菜单</string>
    <string name="about">关于</string>
    <string name="exit">退出</string>
    <string name="ok">确定</string>
	<string name="back">返回</string>
</resources>

 

2.res/layout/main.xml和about.xml

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/main_menu"
    />
</LinearLayout>

 

about.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" android:text="@string/about_me"/>
</LinearLayout>

 

3,res/menu/menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu
  xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:title="@string/about" android:id="@+id/about">
    </item>
    <item android:title="@string/exit" android:id="@+id/exit">
    </item>
</menu>

 

4.A011Activity.java和AboutActivity.java

A011Activity.java

package com.cottsoft.android;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;

public class A011Activity extends Activity {
	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		MenuInflater inflater = getMenuInflater();
		inflater.inflate(R.menu.menu, menu);
		return true;
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		int item_id = item.getItemId();
		switch (item_id) {
			case R.id.about:
				Intent intent = new Intent();
				intent.setClass(A011Activity.this, AboutActivity.class);
				startActivity(intent);
				A011Activity.this.finish();
				break;
			case R.id.exit:
				A011Activity.this.finish();
				break;
		}
		return true;
	}

}

 

AboutActivity.java

/**********************************************
  * @author  Simon Hoo ([e-mail])
  * @contact QQ:9930323 MSN: [e-mail]
  * @OnlineSupport: http://www.cottsoft.com
  * @Create  2011-4-4
  * @version V1.0
  ********************************************/
package com.cottsoft.android;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class AboutActivity extends Activity {

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

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		menu.add(0,0,0,R.string.ok);
		menu.add(0,0,0,R.string.back);
		return true;
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		int item_id = item.getItemId();
		switch(item_id){
			case 0:
			case 1:
				Intent intent = new Intent();
				intent.setClass(AboutActivity.this, A011Activity.class);
				startActivity(intent);
				AboutActivity.this.finish();
				break;
		}
		return true;
	}

}