Android开发技巧不同状态的Button

使用XML实现按钮改变焦点设置背景图，获得焦点时，获得焦点并按下，失去焦点时，默认时...

新建res/drawable/button.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/focusimage"
/>
<!-- 获得焦点并按下 -->
<item
android:state_focused="true"
android:state_pressed="true"
android:drawable="@drawable/clickimage"
/>
<!-- 失去焦点时 -->
<item
android:state_focused="false"
android:state_pressed="true"
android:drawable="@drawable/clickimage"
/>
<!-- 默认时 -->
<item android:drawable="@drawable/normal"/>
</selector>

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <Button
        android:layout_marginTop="20dp"
        android:id="@+id/button"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="不同状态的Button" 
        android:background="@drawable/button"/>

</LinearLayout>