1 - (id)initWithCoder:(NSCoder *)aDecoder 2 { 3     self = [super initWithCoder:aDecoder]; 4     NSLog(@"hello initWithCoder"); 5     //1 6     NSURLRequest *request = [[NSURLRequest alloc] initWithURL:[NSURL URLWithString:@"https://www.okcoin.com/api/ticker.do"]]; 7     //2 8     NSURLSession *session = [NSURLSession sharedSession]; 9     //310     NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {11         if (!error) {12             //413             NSHTTPURLResponse *httPResponse = (NSHTTPURLResponse *)response;14             //515             if (httpResponse.statusCode == 200) {16                 //617                 NSString *string = [[NSString alloc] initWithData:data encoding:NSStringEncodingConversionAllowLossy];18                 NSLog(@"%@",string);19             }20         }21     }];22     //723     [dataTask resume];24     25     return self;26 }

NSURLSession *session = [NSURLSession sharedSession];

NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration];