Advanced android layout: making a ListView divider from a layer-list

问题

Refer to the image below to understand what I'm trying to do. It should be obvious from the image provided. It seems like this should be pretty simple.

The question is, why is the tiled middle section offset by an inconsistent amount for each list entry?

product_list.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="wrap_content"
        android:layout_height="fill_parent">

    <ListView android:id="@+id/android:list"
              android:layout_width="wrap_content"
              android:layout_height="fill_parent"
              android:divider="@drawable/product_list_divider"
              android:background="@drawable/main_background_bitmap"/>
    <TextView android:id="@+id/android:empty"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:text="No results."/>
</LinearLayout>

product_list_divider.xml

<layer-list
    xmlns:android="http://schemas.android.com/apk/res/android" >
    <item>
        <bitmap
            android:src="@drawable/shelf_middle"
            android:tileMode="repeat"/>
    </item>
    <item>
        <bitmap
            android:src="@drawable/shelf_left"
            android:gravity="left"/>
    </item>
    <item>
        <bitmap
            android:src="@drawable/shelf_right"
            android:gravity="right"/>
    </item>
</layer-list>

回答1:

I ended up abandoning the repeat tile mode and did it like this instead:

<?xml version="1.0" encoding="utf-8"?>
<layer-list
    xmlns:android="http://schemas.android.com/apk/res/android" >
    <item>
        <bitmap
            android:src="@drawable/bg"
            android:tileMode="repeat" />
    </item>
    <item>
        <bitmap
            android:src="@drawable/shelf_shine"/>
    </item>
    <item>
        <bitmap
            android:src="@drawable/shelf_middle_stretch"
            android:gravity="bottom|fill_horizontal"/>
    </item>
    <item>
        <bitmap
            android:src="@drawable/shelf_side_left"
            android:gravity="left|bottom"/>
    </item>
    <item>
        <bitmap
            android:src="@drawable/shelf_side_right"
            android:gravity="right|bottom"/>
    </item>
    <item>
        <bitmap
            android:src="@drawable/shelf_left"
            android:gravity="left|bottom"/>
    </item>
    <item>
        <bitmap
            android:src="@drawable/shelf_right"
            android:gravity="right|bottom"/>
    </item>
</layer-list>

来源：https://stackoverflow.com/questions/8061887/advanced-android-layout-making-a-listview-divider-from-a-layer-list