Android中Button自定义点击效果

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

    <item android:drawable="@drawable/pressed" android:state_enabled="true" android:state_focused="true"/>
    <item android:drawable="@drawable/pressed" android:state_enabled="true" android:state_pressed="true"/>
    <item android:drawable="@drawable/normal"/> <!-- 默认时的背景图片，必须在最后呀，否则无效-->

</selector>

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/selector"
    android:text="自定义Btn点击效果" />

android:state_enabled   设置是否响应事件,指所有事件

另外，需要注意selector中 `item` 的顺序：一旦前面的一个 `item` 已经满足匹配的状态，后面的 `item` 就不会去执行了。

android:state_pressed

Boolean. "true" if this item should be used when the object is pressed (such as when a button is touched/clicked); "false" if this item should be used in the default, non-pressed state.

如果是true，当被点击时显示该图片，如果是false没被按下时显示默认。

android:state_focused

Boolean. "true" if this item should be used when the object is focused (such as when a button is highlighted using the trackball/d-pad); "false" if this item should be used in the default, non-focused state.

true，获得焦点时显示；false，没获得焦点显示默认。

android:state_selected

Boolean. "true" if this item should be used when the object is selected (such as when a tab is opened); "false" if this item should be used when the object is not selected.

true，当被选择时显示该图片；false，当未被选择时显示该图片。

android:state_checkable
Boolean. "true" if this item should be used when the object is checkable; "false" if this item should be used when the object is not checkable. (Only useful if the object can transition between a checkable and non-checkable widget.)
true，当CheckBox能使用时显示该图片；false，当CheckBox不能使用时显示该图片。

android:state_checked

Boolean. "true" if this item should be used when the object is checked; "false" if it should be used when the object is un-checked.

true，当CheckBox选中时显示该图片；false，当CheckBox为选中时显示该图片。

android:state_enabled

Boolean. "true" if this item should be used when the object is enabled (capable of receiving touch/click events); "false" if it should be used when the object is disabled.

true，当该组件能使用时显示该图片；false，当该组件不能使用时显示该图片。

android:state_window_focused

Boolean. "true" if this item should be used when the application window has focus (the application is in the foreground), "false" if this item should be used when the application window does not have focus (for example, if the notification shade is pulled down or a dialog appears).

true，当此activity获得焦点在最前面时显示该图片；false，当没在最前面时显示该图片。

<!-- 以下是配置button中的文字效果 -->
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true" android:color="#FFF" />
    <item android:state_focused="true" android:color="#FFF" />
    <item android:state_pressed="true" android:color="#FFF" />
    <item android:color="#000" />
</selector>