selector - iOS Use callback -

please excuse english, i'm french.

so, i'm newbie in ios development. i've developed method must call callback function after async task. i've made search selectors, can't understand how works...

this code :

nsstring *const baseurlstring = @"http://mywebsite.fr/"; + (void) getadverts:(sel *)myselector { // 1 nsurl *baseurl = [nsurl urlwithstring:[nsstring stringwithformat:baseurlstring]];  // 2 afhttpclient *client = [[afhttpclient alloc] initwithbaseurl:baseurl]; [client registerhttpoperationclass:[afjsonrequestoperation class]]; [client setdefaultheader:@"accept" value:@"application/json"]; [client getpath:@"jsoncall"      parameters:nil         success:^(afhttprequestoperation *operation, id responseobject) {             nsdictionary *jsondict = (nsdictionary *) responseobject;             nsarray *adverts = [jsondict objectforkey:@"advert"];              nsmutablearray *advertlist = [[nsmutablearray alloc] init];             advert *advert = [[advert alloc] init];              [adverts enumerateobjectsusingblock:^(id obj ,nsuinteger idx, bool *stop){                 advert.identifier = [(nsnumber *)[obj objectforkey:@"id"] integervalue];                 advert.title = [obj objectforkey:@"title"];                 advert.size = [obj objectforkey:@"size"];                 nslog(@"id:%d size:%@", advert.identifier, advert.size);                 [advertlist addobject:advert];             }];               // use selector callback function             [self performselector:myselector withobject:@"test"];         }         failure:^(afhttprequestoperation *operation, nserror *error) {             uialertview *av = [[uialertview alloc] initwithtitle:@"error retrieving weather"                                                          message:[nsstring stringwithformat:@"%@",error]                                                         delegate:nil                                                cancelbuttontitle:@"ok" otherbuttontitles:nil];             [av show];          }  ]; } 

the "caller" code :

- (void)viewdidload {     [super viewdidload];     [serverhelper getadverts:@selector(myselector)]; }  - (void)myselector {     nslog(@"selector ok"); } 

here error : unrecognized selector sent class

thanks lot

you aren't quite passing selector correctly , aren't calling properly.

you don't want pass pointer sel, need sel. method should be:

+ (void) getadverts:(sel)myselector { 

however, @ moment have:

[self performselector:myselector withobject:@"test"]; 

in instance self refers class in getadverts class method has been defined. not instance of class myselector instance has been declared.

if want way need pass in object want selector called on. getadverts method needs like:

+ (void) getadvertswithtarget:(id)target selector:(sel)myselector { 

and callback using like:

[target performselector:myselector]; 

and call follows:

[serverhelper getadvertswithtarget:self selector:@selector(myselector)];