在Activity中内嵌一个ListView该怎么设置

在Activity中内嵌一个ListView该如何设置？

图中浅色部分想做成一个listview，怎样设置这个listview的布局文件？是单独设置一个布局文件还是在整个Activity的布局文件中，定义一个listview标签，然后在标签中设置？
要使用findViewById把这个listview找到吗？？
求高人指点。

------解决方案--------------------
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class ListViewA extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ListView lv= (ListView)findViewById(R.id.listview);

// create the grid item mapping
String[] from = new String[] {"rowid", "col_1", "col_2", "col_3"};
int[] to = new int[] { R.id.item1, R.id.item2, R.id.item3, R.id.item4 };

// prepare the list of all records
List<HashMap<String, String>> fillMaps = new ArrayList<HashMap<String, String>>();
for(int i = 0; i < 10; i++){
HashMap<String, String> map = new HashMap<String, String>();
map.put("rowid", "" + i);
map.put("col_1", "col_1_item_" + i);
map.put("col_2", "col_2_item_" + i);
map.put("col_3", "col_3_item_" + i);
fillMaps.add(map);
}

// fill in the grid_item layout
SimpleAdapter adapter = new SimpleAdapter(this, fillMaps, R.layout.grid_item, from, to);
lv.setAdapter(adapter);
}
}
main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="@+id/main"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_height="fill_parent"
android:layout_width="fill_parent">
<!-- Header -->
<LinearLayout android:id="@+id/header"
android:background="#ff347c12"
android:layout_height="wrap_content"
android:layout_width="fill_parent"
>
<TextView android:id="@+id/item1"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:width="20dip"
android:height="30dip"
/>
<TextView android:id="@+id/item2"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:text="col_1_h"
android:width="100dip"
android:height="30dip"
/>
<TextView android:id="@+id/item3"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:text="col_2_h"
android:width="100dip"
android:height="30dip"
/>
<TextView android:id="@+id/item4"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:text="col_3_h"
android:width="100dip"
android:height="30dip"
/>
</LinearLayout>

<!-- List Divider -->
<View android:layout_width="fill_parent"
android:layout_height="1dip"
android:background="?android:attr/listDivider" />

<!-- ListView (grid_items) -->
<LinearLayout android:id="@+id/layout"
android:layout_width="wrap_content"