Android_Button按下改变背景和字体颜色

Button控件：

<Button
android:id="@+id/btn_gaibian"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="100"
android:background="@drawable/button_select"
android:textColor="@drawable/button_font_style"
android:text="改变"
android:textSize="18dp" />

button_select.xml代码：
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/anxia_p" android:state_pressed="false"></item>
<item android:drawable="@drawable/taiqi_n" android:state_pressed="true"></item>
</selector>

button_font_style.xml代码：

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true" android:color="#fff"/>
<item android:state_focused="true" android:color="#fff"/>
<item android:color="#000" />
</selector>