3.乐学成语----------显示主界面

1.主界面的设计采取选项卡组件

在res的drawable-hdpi目录下拷贝需要的图片素材，在res/layout目录中新建activity_main.xml布局，代码如下：

<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"
android:theme="@android:style/Theme.NoTitleBar"
tools:context=".MainActivity" >

<TabHost
android:id="@android:id/tabhost"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<TabWidget
android:id="@android:id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</TabWidget>
<FrameLayout
android:id="@android:id/tabcontent"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="@+id/tab1"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
</LinearLayout>
<LinearLayout
android:id="@+id/tab2"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
</LinearLayout>
<LinearLayout
android:id="@+id/tab3"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
</LinearLayout>
</FrameLayout>
</LinearLayout>
</TabHost>
</RelativeLayout>2.在res的values目录的strings.xml文件中定义所需字符串，代码如下：
<?xml version="1.0" encoding="utf-8"?>
<resources>

<string name="app_name">HappyIdiom</string>
<string name="action_settings">Settings</string>
<string name="hello_world">Hello world!</string>
<string name="title_activity_main">MainActivity</string>
<string name="title_study">学习</string>
<string name="title_search">搜搜</string>
<string name="title_game">游戏</string>
<string name="title_save">收藏</string>
<string name="title_help">帮助</string>

<string-array name="category">
<item>动物类</item>
<item>自然类</item>
<item>人物类</item>
<item>季节类</item>
<item>数字类</item>
<item>寓言类</item>
<item>其他类</item>
</string-array>

<string name="title_activity_study">StudyActivity</string>

</resources>3.在activity包下新建MainActivity继承自Activity,代码如下：
public class MainActivity extends TabActivity {
private TabHost tabHost;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);//取消标题栏
setContentView(R.layout.activity_main);
tabHost = getTabHost();
addTab("study",R.string.title_study,R.drawable.search,StudyActivity.class);
addTab("search",R.string.title_search,R.drawable.search,StudyActivity.class);
addTab("game",R.string.title_game,R.drawable.game,StudyActivity.class);
addTab("save",R.string.title_save,R.drawable.save,StudyActivity.class);
addTab("help",R.string.title_help,R.drawable.search,StudyActivity.class);
}

private void addTab(String tag, int title_introduction, int title_icon, Class ActivityClass){
// TODO Auto-generated method stub
tabHost.addTab(tabHost.newTabSpec(tag).setIndicator(getString(title_introduction),
getResources().getDrawable(title_icon)).setContent(new Intent(this,ActivityClass)));
}

@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);
return true;
}

}结果图为：