Splitting big tasks into small tasks is often one of the best ways to solve a problem. Thus, in the next few exercises, we will split each request/method into a 7 step process. In the source code, I have commented each of these steps to assist you as you implement the requests.
7 Step Process
NSURLRequest or NSMutableURLRequest using the URLNSMutableURLRequest, you may need to configure the request‘s header fields and HTTP bodyNSURLSession singleton, issue the request and specify a completion handlerNSDictionary, NSArray, or [String:AnyObject], ...原文:http://www.cnblogs.com/dagon/p/4782415.html