問題描述
狀態列表可繪製在預蜂窩版本上無法正常工作 (State list drawable not working properly on pre-honeycomb versions)
I'm making an application with checklists that primarily targets Android 4.0. There I use this selector as the background of my list item:
<?xml version="1.0" encoding="utf-8"?>
<selector
xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:state_pressed="true"
android:drawable="@drawable/checklist_selector_pressed" />
<item
android:state_focused="true"
android:drawable="@drawable/checklist_selector_focused" />
<item
android:state_activated="true"
android:drawable="@drawable/checklist_selector_selected" />
<item
android:drawable="@android:color/transparent" />
"state_activated" seems to do the trick as the checked items do not stay visibly checked if I take that selector away. However, this only works on post-Honeycomb versions. Anything before that ignores state_activated (or state_checked and state_selected) and only accepts state_pressed (the lines color themselves when I touch them but do not stay colored afterwards). This is really confusing to me so I would appreciate any advice on the matter.
Thanks.
參考解法
方法 1:
The android:state_activated attribute does not exist prior to Honeycomb. I suggest that you maintain two versions of the drawable: a default version in res/drawable that does not reference android:state_activated (or any other states that were introduced in Honeycomb) and a Honeycomb-and-later version in res/drawable-v11 that does.