按钮无效时如何变灰

Question

问题如题，求解

Answer 1

看来都喜欢答非所问啊
[code="xml"]
 android:state_enabled="false"
android:drawable="@drawable/btn_red" />
android:state_pressed="true"
android:state_enabled="true"
android:drawable="@drawable/btn_orange" />
android:state_focused="true"
android:state_enabled="true"
android:drawable="@drawable/btn_orange" />
android:state_enabled="true"
android:drawable="@drawable/btn_black" />
[/code]