How to wait dispatch asyn finish? - xcode

Question

I used dispatch async to get som info from facebook , but i can't know when asyn finish
-(void)shareScoreViaFB:(int)score{
__block NSDictionary * dic;
ACAccountStore *_accStore=[[ACAccountStore alloc]init];
ACAccountType *_accType =[_accStore accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierFacebook];
NSDictionary *options = #{
ACFacebookAppIdKey:_mAppID,
ACFacebookPermissionsKey: #[#"publish_actions"],
ACFacebookAudienceKey: ACFacebookAudienceFriends
};
[_accStore requestAccessToAccountsWithType:_accType options:options completion:^(BOOL granted, NSError *e) {
if (granted) {
NSArray *accounts = [_accStore accountsWithAccountType:_accType];
_accFB = [accounts lastObject];
// [self openShareDialog];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
dic =[self getListScore];
dispatch_sync(dispatch_get_main_queue(), ^{
NSLog(#"data1: %#",dic);
});
});
};
}];
}
And method to get info
-(NSDictionary *)getListScore{
__block NSDictionary * dict=nil;
NSString *url =[NSString stringWithFormat:#"https://graph.facebook.com/%#/scores",_mAppID];
NSURL * strURL =[NSURL URLWithString:url];
NSDictionary * parameters =[NSDictionary dictionaryWithObjectsAndKeys:#"score,user",#"fields", nil];
SLRequest * request =[SLRequest requestForServiceType:SLServiceTypeFacebook
requestMethod:SLRequestMethodGET URL:strURL parameters:parameters];
request.account = _accFB;
[request performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) {
if (!error && responseData) {
dict = [NSJSONSerialization JSONObjectWithData:responseData options:0 error:nil];
NSLog(#"%#",dict[#"data"]);
// return dict[#"data"];
}
}];
return dict;
}
When i run' the log show:
- dict1: null.
- dict: OK (this show true value).
How i wait for dispatch_asyn finish and set this value to main interface?

Answer 1

Try doing it as follows:
-(void)shareScoreViaFB:(int)score{
__block NSDictionary * dic;
ACAccountStore *_accStore=[[ACAccountStore alloc]init];
ACAccountType *_accType =[_accStore accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierFacebook];
NSDictionary *options = #{
ACFacebookAppIdKey:_mAppID,
ACFacebookPermissionsKey: #[#"publish_actions"],
ACFacebookAudienceKey: ACFacebookAudienceFriends
};
[_accStore requestAccessToAccountsWithType:_accType options:options completion:^(BOOL granted, NSError *e) {
if (granted) {
NSArray *accounts = [_accStore accountsWithAccountType:_accType];
_accFB = [accounts lastObject];
NSString *url =[NSString stringWithFormat:#"https://graph.facebook.com/%#/scores",_mAppID];
NSURL * strURL =[NSURL URLWithString:url];
NSDictionary * parameters =[NSDictionary dictionaryWithObjectsAndKeys:#"score,user",#"fields", nil];
SLRequest * request =[SLRequest requestForServiceType:SLServiceTypeFacebook
requestMethod:SLRequestMethodGET URL:strURL parameters:parameters];
request.account = _accFB;
[request performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) {
if (!error && responseData) {
dict = [NSJSONSerialization JSONObjectWithData:responseData options:0 error:nil];
NSLog(#"%#",dict[#"data"]);
dispatch_sync(dispatch_get_main_queue(), ^{
NSLog(#"data1: %#",dic);
});
}
}];
};
}];
}