ios中的网络请求

GET请求
NSString *urlString =
@"http://";//请求的地址

// 对于中文的话要对请求地址实行 UTF－8编码

[urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSURLRequest *Request = [NSURLRequest
requestWithURL:urlString];

NSURLConnection *connect = [NSURLConnection
connectionWithRequest:Request
delegate:self];

[connect start];
POST请求

NSMutableURLRequest *request = [NSMutableURLRequest
requestWithURL:[NSURL
URLWithString:urlString]];

NSString *bodyStr = [NSString
stringWithFormat:@"username=%@&password=%@"];

NSData *body = [bodyStr
dataUsingEncoding:NSUTF8StringEncoding];

[request setHTTPBody:body];

[request setHTTPMethod:@"POST"];

NSURLConnection *connect = [NSURLConnection
connectionWithRequest:request
delegate:self];

[connect start];
代理方法的问题
代理方法比较多，比较分散
要处理一个请求，需要在很多地方编写代码，不利于逻辑实现，代码编写，调试和维护以及拓展