Android-key-of-love/app/src/main/res/drawable/btn_keyboard_function.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- Shift键激活状态 -->
    <item android:state_activated="true">
        <shape android:shape="rectangle">
            <solid android:color="#4CAF50"/>
            <corners android:radius="@dimen/sw_4dp"/>
            <stroke android:width="@dimen/sw_1dp" android:color="#388E3C"/>
        </shape>
    </item>
    
    <!-- 按下状态 -->
    <item android:state_pressed="true">
        <shape android:shape="rectangle">
            <solid android:color="#9E9E9E"/>
            <corners android:radius="@dimen/sw_4dp"/>
            <stroke android:width="@dimen/sw_1dp" android:color="#757575"/>
        </shape>
    </item>
    
    <!-- 默认状态 -->
    <item>
        <shape android:shape="rectangle">
            <solid android:color="#E0E0E0"/>
            <corners android:radius="@dimen/sw_4dp"/>
            <stroke android:width="@dimen/sw_1dp" android:color="#BDBDBD"/>
        </shape>
    </item>
</selector>