Be sure to include a leading and trailing blank in your class attribute string check.

一定要在class属性字符串检查中包含前导和尾部空格。

youdao

Any string value can be placed in the custom attribute on the asset; however, the value is for searching and view-only purposes in the RAM clients.

任意字符串值都可以加入资产的自定义属性中；但是，这个值只用于在 RAM 客户端中搜索和查看。

youdao

It retrieves the version attribute in string form.

它获取了字符串格式的版本属性。

youdao

Instead, use the NSShadowAttributeName attribute of the attributed string to set the shadow.

ENGADGET: Apple seeds iOS 6 beta 4 to developers: here's the changelog