ios - 如何通过延迟从方法返回值？

Question

我有一个框架和一个项目。我的框架负责Web服务。

在Project用户中，输入用户名和密码。然后，它通过在框架内调用sendLogin方法来传递这些参数。

在框架内部，需要花费一些时间来检查和验证用户名和密码。如果用户名和密码正确，它将从服务器获取 token 号。

到这里为止一切正常。但是我想知道如何将该 token 发送回主程序吗？

我尝试使用完成方法，但失败了。这是定义:

项目:

- (IBAction)bankLoginPressed:(id)sender
{
    [registerUser sendLogin:^(NSInteger *accessCode){

        NSLog(@"access code ==  %tu ",accessCode);

    }];
}

内部框架

typedef void (^HttpCompletionBlock) (NSInteger *);

-(void) sendLogin :(HttpCompletionBlock)completionHandler
{
    NSString *string = @"https://myserver/customer_authentication";
    NSDictionary *parameters = @{@"member_id": @"1234", @"access_code": @"password", @"device_id":@"874627864"};

    AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    [manager POST:string parameters:parameters progress:nil success:^(NSURLSessionTask *task, id responseObject) {

        NSLog(@"JSON: %@", responseObject);
        if (responseObject[@"secret_token"])
        {

            NSLog(@"Secret is=    %@",responseObject[@"secret_token"]);
            //Here I needd to send back token number????

        }
    }
          failure:^(NSURLSessionTask *operation, NSError *error)
     {
         NSLog(@"Error: %@", error);
     }];
}

Answer 1

typedef void (^HttpCompletionBlock)     (NSString *token, NSError *error);

-(void) sendLogin :(HttpCompletionBlock)completionHandler
{
    NSString *string = @"https://myserver/customer_authentication";
    NSDictionary *parameters = @{@"member_id": @"1234", @"access_code": @"password", @"device_id":@"874627864"};

     AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    [manager POST:string parameters:parameters progress:nil success:^(NSURLSessionTask *task, id responseObject) {

    NSLog(@"JSON: %@", responseObject);
    if (responseObject[@"secret_token"])
    {

        NSLog(@"Secret is=    %@",responseObject[@"secret_token"]);
        //Here I needd to send back token number????
        return completionHandler(responseObject[@"secret_token"],nil);

      }
    }
      failure:^(NSURLSessionTask *operation, NSError *error)
      {
          NSLog(@"Error: %@", error);
          return completionHandler(nil,error);
      }];
}

- (IBAction)bankLoginPressed:(id)sender
{
    [registerUser sendLogin:^(NSString *token, NSError *error){
        if(error == nil)
        {
            NSLog(@"access code ==  %@ ",token);
        }
        else
        {       
            NSLog(@"Error ==  %@ ",error);
        }

    }];
}