更改TabHost里的第一个LinearLayout为RelativeLayout。并在TabWidget中添加android:layout_alignParentBottom="true"
<FrameLayout 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"
tools:context=".MainActivity" >
<TabHost
android:id="@android:id/tabhost"
android:layout_width="match_parent"
android:orientation="vertical"
android:layout_height="match_parent" >
<RelativeLayout
android:id="@+id/RelativeLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<TabWidget
android:id="@android:id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true" >
</TabWidget>
<FrameLayout
android:id="@android:id/tabcontent"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<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>
<LinearLayout
android:id="@+id/tab4"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</LinearLayout>
</FrameLayout>
</RelativeLayout>
</TabHost>
</FrameLayout>