seekBar背景：

<span style="font-family:Comic Sans MS;font-size:14px;"><?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

    <!-- 背景 -->
    <item
        android:id="@android:id/background"
        android:paddingBottom="3px"
        android:paddingTop="3px">
        <shape>
            <!-- 角度 -->
            <corners android:radius="10dip" />

            <!-- 边框 -->
            <stroke
                android:width="0.5dp"
                android:color="#7c7d7c" />

            <!-- 填充颜色渐变 -->
            <gradient
                android:angle="270"
                android:centerColor="#00dddedf"
                android:centerY="0.45"
                android:endColor="#00dddedf"
                android:startColor="#00dddedf" />
        </shape>
    </item>
    
    <!-- 进度 -->
    <item
        android:id="@android:id/progress"
        android:paddingBottom="3px"
        android:paddingTop="3px">
        <clip>
            <shape>
                <stroke
                    android:width="0.5dp"
                    android:color="#7c7d7c" />

                <corners android:radius="10dip" />

                <gradient
                    android:angle="270"
                    android:centerColor="#e7e8ed"
                    android:centerY="0.45"
                    android:endColor="#f3f5f7"
                    android:startColor="#dbdfe4" />
            </shape>
        </clip>
    </item>

</layer-list>
</span>

<span style="font-family:Comic Sans MS;font-size:14px;"><?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">  
    <!-- 按下状态 -->  
    <item android:state_pressed="true" android:drawable="@drawable/thumb_select" />  
  
    <!-- 普通无焦点状态 -->  
    <item android:state_focused="false" android:state_pressed="false"  
        android:drawable="@drawable/thumb_bg" />  
</selector></span> 

<span style="font-family:Comic Sans MS;font-size:14px;"><SeekBar
            android:id="@+id/seekBar1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:max="9"
            android:maxWidth="300dp"
            android:minWidth="300dp"
            android:maxHeight="20dp"
            android:minHeight="20dp"
            android:paddingLeft="4dp"
            android:paddingRight="4dp"
            android:progressDrawable="@drawable/seekbar_define_color_style"
            android:thumb="@drawable/thumb_background" /></span>