According to CommonsWare answer, please read this guide: Maintaining Compatibility
Here you would find:
The RecyclerView
and CardView
widgets are available in earlier
versions of Android through the Android v7 Support Library with these
limitations:
CardView
falls back to a programmatic shadow implementation using additional padding.
CardView
does not clip its children views that intersect with rounded corners.
Dependencies:
To use these features in versions of Android earlier than 5.0 (API
level 21), include the Android v7 Support Library in your project as a
Gradle dependency:
dependencies {
compile 'com.android.support:appcompat-v7:21.0.+'
compile 'com.android.support:cardview-v7:21.0.+'
compile 'com.android.support:recyclerview-v7:21.0.+'
}
Moreover in source code of RecyclerView
, you would find this line
if (className.length() != 0) { // Can't use isEmpty since it was added in API 9.
className = getFullClassName(context, className);
I don't know a guy using API 9, but it seems to be that it's really well backward supported kibrary.
Check also: android support(cardView, RecyclerView)library in older versions with target kitkat
Hope it help