game_android/KeepDancing/unity-android-resources/res/drawable/ui_send.xml

<?xml version="1.0" encoding="utf-8"?>

<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <!-- 获得焦点时 -->
    <item
        android:state_focused="true"
        android:state_pressed="false"
        android:drawable="@drawable/ui_send_normal"
        />

    <!-- 获得焦点并按下 -->
    <item
        android:state_focused="true"
        android:state_pressed="true"
        android:drawable="@drawable/ui_send_press"
        />
    <!-- 失去焦点时 -->
    <item
        android:state_focused="false"
        android:state_pressed="true"
        android:drawable="@drawable/ui_send_press"
        />

    <!-- 默认时 -->
    <item
       android:drawable="@drawable/ui_send_normal"/>

</selector>