转载:
TabHost是整个Tab的容器,包括两部分,TabWidget和FrameLayout。TabWidget就是每个tab的标签,FrameLayout则是tab内容。
1、如果我们使用extends TabAcitivty,如同ListActivity,TabHost必须设置为@android:id/tabhost 
2、TabWidget必须设置android:id为@android:id/tabs 
3、FrameLayout需要设置android:id为@android:id/tabcontent 
4、参考这儿:<a href="http://blog.csdn.net/flowingflying/archive/2011/04/06/6304289.%3Ca%20href=" http:="" www.2cto.com="" kf="" web="" asp="" "="" target="_blank" class="keylink" style="color: rgb(51, 51, 51); text-decoration: none;">aspx">http://blog.csdn.net/flowingflying/archive/2011/04/06/6304289.aspx
先自定义一个xml文件: 
Java代码  
<?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">  
    <FrameLayout  
        android:id="@android:id/tabcontent"  
        android:layout_width="fill_parent"  
        android:layout_height="fill_parent"  
         android:layout_weight="1.0"  
        android:paddingBottom="53px"/>  
    <TabWidget  
        android:id="@android:id/tabs"  
        android:layout_alignParentBottom="true"  
        android:layout_width="fill_parent"  
        android:layout_height="50px"   
        android:visibility="gone"  
        android:layout_weight="0.0"/>  
        <RadioGroup  
            android:gravity="center_vertical"  
            android:orientation="horizontal"  
            android:id="@+id/main_radio"  
            android:background="@drawable/radiogroup_background"  
            android:layout_width="fill_parent"  
            android:layout_height="50dip"  
            android:layout_gravity="bottom">  
            <RadioButton  
                android:id="@+id/main_index_button"  
                android:layout_marginTop="1.0dip"  
                android:layout_marginRight="5dip"  
                android:text="@string/main_name"  
                android:drawableTop="@drawable/unistall"  
                style="@style/main_tab_bottom"  
                android:background="@drawable/radio_bg"/>  
            <RadioButton  
                android:id="@+id/main_running_button"  
                android:layout_marginTop="1.0dip"  
                android:layout_marginRight="5dip"  
                android:text="@string/run_manager_name"  
                android:drawableTop="@drawable/unistall"  
                style="@style/main_tab_bottom"  
                android:background="@drawable/radio_bg"/>  
            <RadioButton  
                android:id="@+id/main_uninstall_button"  
                android:layout_marginTop="1.0dip"  
                android:text="@string/uninstall_manager_name"  
                android:drawableTop="@drawable/unistall"  
                style="@style/main_tab_bottom"  
                android:background="@drawable/radio_bg"/>  
        </RadioGroup>  
    </LinearLayout>  
</TabHost> 
为了让tabHost显示在下方,要将RadioGroup的layout_gravity设置为bottom,再将FrameLayout的layout_weight设置为1,这样就可以将RadioGroup撑到最下方。style="@style/main_tab_bottom"里面定义了样式文件。
接下来就是在activity中初始化并添加tabhost: 
Java代码  
tabHost = (TabHost) findViewById(android.R.id.tabhost);  
        tabHost.addTab(Constant.tabHost.newTabSpec("Main")  
                .setIndicator(getString(R.string.main_name),null)  
                .setContent(new Intent(this, Main.class)));  
        tabHost.addTab(Constant.tabHost.newTabSpec("RunManager")  
                .setIndicator(getString(R.string.run_manager_name),null)  
                .setContent(new Intent(this, RunManager.class)));  
        tabHost.addTab(Constant.tabHost.newTabSpec("UninstallManager")  
                .setIndicator(getString(R.string.uninstall_manager_name),null)  
                .setContent(new Intent(this, UninstallManager.class))); 
初始化每个RadioButton并为其添加setOnCheck