设置ExpandableListView不显示分割线

<ExpandableListView

        android:id="@+id/expandlist"

       android:layout_width="fill_parent"

       android:layout_height="fill_parent"

        android:background="#ffffff"

       android:cacheColorHint="#00000000"

       android:childDivider="@drawable/list_line"

        android:divider="@null"

       android:listSelector="#00000000" >

</ExpandableListView>