如何使用NSJSONSerialization类参考读取JSON文件？

I need to read a JSON file using the NSJSONSerialization Class Reference, and all the examples that I have found about the use of this class read the content from the webpage itself, instead of reading from a JSON file that has been previously created.Anyone knows how to parse from a JSON file using that class? Thanks.I need to read a JSON file using the NSJSONSeri