Android “?colorPrimary” vs “?attr/colorPrimary”?
问题 I can't find any information about the differences between: android:textColor="?attr/colorPrimary" vs android:textColor="?colorPrimary" I have read that "?attr" means attribute value specified in the current theme, but without "attr" it gives the same result (=color defined in my theme). It behaves similar with other attributes? For example: Does android:background="?attr/selectableItemBackground" equals android:background="?selectableItemBackground" ? Here it's told that it differs. Thanks