自定义CheckBox

<CheckBox
            android:id="@+id/checkbox1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:button="@drawable/checkbox_style"
            android:checked="true" />

checkbox_style文件

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

    <item android:drawable="@drawable/ontract_uploaad_select" android:state_checked="true"/>
    <item android:drawable="@drawable/ontract_uploaad_grey" android:state_checked="false"/>
    <item android:drawable="@drawable/ontract_uploaad_grey"/>

</selector>