<selector xmlns:android="http://schemas.android.com/apk/res/android">  <!-- 無狀態時 -->  <item    android:state_focused="false"    android:state_selected="false"    android:state_pressed="false"    android:state_enabled="true"    android:drawable="@drawable/blue" />  <!-- 選中狀態 -->  <item    android:state_focused="false"    android:state_selected="true"    android:state_pressed="false"    android:state_enabled="true"    android:drawable="@drawable/blue" />  <!-- 獲得焦點 -->  <item    android:state_focused="true"    android:state_selected="false"    android:state_pressed="false"    android:state_enabled="true"    android:drawable="@drawable/blue" />  <!-- 按下時的狀態 -->  <item    android:state_focused="false"    android:state_selected="false"    android:state_pressed="true"    android:state_enabled="true"    android:drawable="@drawable/blue" /></selector>