Andorid 自定义seekbar

<?xml version="1.0" encoding="utf-8"?>
<resources>
   <style name="Widget.SeekBar.Normal" parent="@android:style/Widget.SeekBar">
        <item name="android:maxHeight">8.0dip</item>
        <item name="android:indeterminateOnly">false</item>
        <item name="android:indeterminateDrawable">@android:drawable/progress_indeterminate_horizontal</item>
        <item name="android:progressDrawable">@drawable/seekbar_horizontal</item>
        <item name="android:minHeight">8.0dip</item>
        <item name="android:thumb">@drawable/seek_thumb</item>
        <item name="android:thumbOffset">10.0dip</item>
    </style>    
</resources>

<?xml version="1.0" encoding="UTF-8"?>
<layer-list
  xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@android:id/background" android:drawable="@drawable/seek_bkg" />
    <item android:id="@android:id/secondaryProgress">
        <clip>
            <shape>
                <corners android:radius="2.0dip" />
                <gradient android:startColor="#80ffd300" android:endColor="#a0ffcb00" android:angle="270.0" android:centerY="0.75" android:centerColor="#80ffb600" />
            </shape>
        </clip>
    </item>
    <item android:id="@android:id/progress">
        <clip android:drawable="@drawable/seek" />
    </item>
</layer-list>

    <SeekBar android:id="@+android:id/progresss"
        android:layout_width="fill_parent" android:layout_height="wrap_content"
        android:layout_marginTop="50dip" style="@style/Widget.SeekBar.Normal" />