布局

<android.support.v7.widget.AppCompatSeekBar
                android:id="@+id/vertical_seekbar"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:progressDrawable="@drawable/seekbar_style"
                android:thumb="@drawable/seekbar_thumb"
                />

seekbar_style.xml

<?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:gravity="center_vertical|fill_horizontal">
        <shape android:shape="rectangle">
            <corners android:radius="5dp"/>
            <size android:height="2dp"/>
            <solid android:color="#80b6b6b6"/>
        </shape>
    </item>

    <item
        android:id="@android:id/secondaryProgress"
        android:gravity="center_vertical|fill_horizontal">
        <clip>
            <shape android:shape="rectangle">

                <corners android:radius="5dp"/>
                <size android:height="2dp"/>
                <solid android:color="@color/orange_disenable"/>
            </shape>
        </clip>
    </item>

    <item
        android:id="@android:id/progress"
        android:gravity="center_vertical|fill_horizontal">
        <clip>
            <shape android:shape="rectangle">
                <corners android:radius="5dp"/>
                <size android:height="2dp"/>
                <solid android:color="@color/orange"/>
            </shape>
        </clip>
    </item>
</layer-list>

这里特别注意的就是一定不能忘了加android:gravity="center_vertical|fill_horizontal",不然效果就会背景就会变得很粗，设置的<size android:height="2dp">无效。

seekbar_thumb.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true">
        <shape
            android:shape="oval"
            android:useLevel="false">
            <solid android:color="@color/white"/>
            <size
                android:width="12dp"
                android:height="12dp"/>
        </shape>
    </item>
    <item android:state_focused="true">
        <shape
            android:shape="oval"
            android:useLevel="false">
            <solid android:color="@color/white"/>
            <size
                android:width="12dp"
                android:height="12dp"/>
        </shape>
    </item>
    <item>
        <shape
            android:shape="oval"
            android:useLevel="false">
            <solid android:color="@color/orange"/>
            <size
                android:width="12dp"
                android:height="12dp"/>
        </shape>
    </item>
</selector>