关于tabhost的底部实现，什么都没有显示，求助！

实现部分TabHostActivity.java
package com.map;
import android.app.TabActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.widget.TabHost;
public class TabHostActivity extends TabActivity {
    private TabHost tabHost;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.tabhost);
        tabHost = this.getTabHost();
        initTabs();
    }
    private void initTabs() {
        tabHost.setup(this.getLocalActivityManager());
        // 添加线路规划的tab
        tabHost.addTab(tabHost.newTabSpec("tab1")
          .setIndicator("线路规划",getResources().getDrawable(R.drawable.tabpic1))
          .setContent(new Intent(this, FirstActivity.class)));
   
        // 添加城市名片的tab
        tabHost.addTab(tabHost.newTabSpec("tab5")
          .setIndicator("城市名片",getResources().getDrawable(R.drawable.tabpic5))
          .setContent(new Intent(this, FifthActivity.class)));
      
    }
}
xml布局文件tabhost.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas. android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TabHost
        android:id="@+id/edit_item_tab_host"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:orientation="vertical"
            android:padding="5dp" >

            <FrameLayout
                android:id="@android:id/tabcontent"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:padding="5dp" />

            <TabWidget
                android:id="@android:id/tabs"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_weight="0" />
        </LinearLayout>
    </TabHost>

</LinearLayout>