android TabHost(选项卡)的使用方法

<?xml version="1.0" encoding="utf-8"?>

<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost" android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <LinearLayout android:orientation="vertical"
        android:layout_width="fill_parent" android:layout_height="fill_parent">

        <TabWidget android:id="@android:id/tabs"
            android:layout_alignParentBottom="true"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"/>

        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent" />

    </LinearLayout>

</TabHost>

public class MainActivity extends TabActivity {

    private TabHost my_tabhost; 
    private TabWidget my_tabwidget;
    private int i,k;
    private TextView tv;

    private String[] tabMenu = { "系统", "硬件", "操作"};
    private Intent intent0, intent1, intent2;
    private Intent[] intents = { intent0, intent1, intent2};
    private TabHost.TabSpec tabSpec0, tabSpec1, tabSpec2, tabSpec3;
    private TabHost.TabSpec[] tabSpecs = { tabSpec0, tabSpec1, tabSpec2, tabSpec3};

    public static Context mContext;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
       　　　　　　 　　// 不要窗体标题
        　　　　　　　requestWindowFeature(Window.FEATURE_NO_TITLE);
        　　　　　　 setContentView(R.layout.activity_main);
        setContentView(R.layout.activity_main);

        my_tabhost = getTabHost();

        intent0 = new Intent(this, system.class);
        intent1 = new Intent(this, hardware.class);
        intent2 = new Intent(this, operation.class);

        tabSpec0 = my_tabhost.newTabSpec("system").setIndicator(tabMenu[0],null).
                setContent(intent0);
        tabSpec1 = my_tabhost.newTabSpec("hardware").setIndicator(tabMenu[1],null).
                setContent(intent1);
        tabSpec2 = my_tabhost.newTabSpec("operation").setIndicator(tabMenu[2],null).
                setContent(intent2);

        my_tabhost.addTab(tabSpec1);
        my_tabhost.addTab(tabSpec0);
        my_tabhost.addTab(tabSpec2);
<br> 　　　　            // 设置默认选中的选项卡为第2个      
                     my_tabhost.setCurrentTab(1);

    }

}