res与res-auto的区别

Solution:

Upgrade to latest SDK & ADT version (fixed was released since r17) and usehttp://schemas.android.com/apk/res-auto as custom attributes' namespace URI, see Revisions for ADT 17.0.0:

Added support for custom views with custom attributes in libraries. Layouts using custom attributes must use the namespace URI http://schemas.android.com/apk/res-auto instead of the URI that includes the app package name. This URI is replaced with the app specific one at build time.

res与res-auto的区别

通常我们在布局文件中使用自定义属性的时候
会这样写

xmlns:app="http://schemas.android.com/apk/res/包路径"

但如果你当前工程是做为lib使用，那么你如上所写 ，会出现找不到自定义属性的错误 。
这时候你就可以 写成

xmlns:app="http://schemas.android.com/apk/res-auto"