如图自定义的Switch样式：

5421606984766_.pic.jpg

需要注意的是：switch的大小是跟thumb的大小有关
下面以样式二为例：

switch_track_selector_new.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/switch_track_bg_selected" android:state_checked="true"/>
    <item android:drawable="@drawable/switch_track_bg_normal" android:state_checked="false"/>
</selector>

switch_track_bg_selected.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">

    <solid android:color="@color/switch_track_selected"/>
    <size  android:width="@dimen/switch_track_width"
        android:height="@dimen/switch_track_height"/>
    <corners android:radius="20dp"/>

</shape>

switch_track_bg_normal.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@color/switch_track_normal"/>
    <size  android:width="@dimen/switch_track_width"
        android:height="@dimen/switch_track_height"/>
    <corners android:radius="20dp"/>

</shape>

switch_thumb_selector_new.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:drawable="@drawable/switch_thumb_bg_selected" android:state_checked="true"/>
    <item android:drawable="@drawable/switch_thumb_bg_normal" android:state_checked="false"/>

</selector>

switch_thumb_bg_selected.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <stroke android:width="@dimen/switch_thumb_stroke_width" android:color="@color/switch_track_selected"/>
    <solid android:color="@color/switch_thumb_normal"/>
    <size  android:width="@dimen/switch_track_height"
        android:height="@dimen/switch_track_height"/>

</shape>

switch_thumb_bg_normal.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <stroke android:width="@dimen/switch_thumb_stroke_width" android:color="@color/switch_track_normal"/>
    <solid android:color="@color/switch_thumb_normal"/>
    <size  android:width="@dimen/switch_track_height"
        android:height="@dimen/switch_track_height"/>

</shape>

switch引用：

<Switch
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:thumb="@drawable/switch_thumb_selector_new"
            android:track="@drawable/switch_track_selector_new"/>

详细参考： Android Switch自定义样式