android學習：菜單（Menu）的使用

MainActivity.java

package com.example.examples_04_13;import android.os.Bundle;import android.app.Activity;import android.content.Intent;import android.view.Menu;import android.view.MenuItem;public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}/* 處理菜單事件 */public boolean onOptionsItemSelected(MenuItem item) {// TODO Auto-generated method stubint item_id = item.getItemId();switch (item_id) {case R.id.about:Intent intent = new Intent();intent.setClass(MainActivity.this, Activity2.class);startActivity(intent);MainActivity.this.finish();break;case R.id.exit:MainActivity.this.finish();default:break;}return super.onOptionsItemSelected(item);}}

Activity2.java

package com.example.examples_04_13;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;public class Activity2 extends Activity{@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.layout2);}/* 建立Menu */public boolean onCreateOptionsMenu(Menu menu) {// 為Menu新增內容menu.add(0, 0, 0, R.string.ok);menu.add(0, 1, 1, R.string.back);return super.onCreateOptionsMenu(menu);}/* 處理Menu的事件 */public boolean onOptionsItemSelected(MenuItem item) {int item_id = item.getItemId();switch (item_id) {case 0:Activity2.this.finish();break;case 1:Intent intent = new Intent();intent.setClass(Activity2.this, MainActivity.class);startActivity(intent);Activity2.this.finish();break;default:break;}return super.onOptionsItemSelected(item);}}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity" >    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="MainActivity" /></RelativeLayout>

layout2.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical" ><TextView     android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="Activity2"/>    </LinearLayout>

res/menu/main.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android" >    <item        android:id="@+id/about"        android:title="關於"/>    <item        android:id="@+id/exit"        android:title="退出"/></menu>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.examples_04_13"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="17" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.example.examples_04_13.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <activity             android:name="com.example.examples_04_13.Activity2">                    </activity>    </application></manifest>