为什么我不能从我的块返回一个对象？ [英] Why can't I return an object from my block?

问题描述

我试图返回一个的NSMutableArray 从我在我的方法块，但是当我添加行返回[responseString JSONValue]; ，我得到一些编译器警告。

   - （NSMutableArray的*）getTodayData：（NSDate的*）今日
{
        ASIFormDataRequest *请求= [[[ASIFormDataRequest页头] initWithURL：URL]自动释放];
        [要求setPostValue：[DATEFORMAT stringFromDate：今天] forKey：@target_date];
        NSError *错误=请求错误]        [要求setCompletionBlock：^ {
            * NSString的responseString;
            如果（！错误）{
                responseString = [要求responseString]
                返回[responseString JSONValue]
            }其他{
                的NSLog（@错误：％@，错误）;
            }
        }];
        [要求setFailedBlock：^ {
            * NSString的responseString;
            如果（！错误）{
                responseString = [要求responseString]
            }其他{
                的NSLog（@错误：％@，错误）;
            }
        }];
        [请求startAsynchronous]
}
 

解决方案

的 setCompletionBlock：和 setFailedBlock：方法在 ASIFormDataRequest 不接受返回值块。你需要调整你的code，以便有没有返回值。

例如：

   - （无效）viewDidLoad中
{
  [个体经营getTodayData：self.datePicker.date];
} - （无效）getTodayData：（NSDate的*）今日
{
      self.appointmentsArray = [NSArray的阵列] //现在设置为空值，所以表视图显示什么      ASIFormDataRequest *请求= [[[ASIFormDataRequest页头] initWithURL：URL]自动释放];
      [要求setPostValue：[DATEFORMAT stringFromDate：今天] forKey：@target_date];
      NSError *错误=请求错误]      [要求setCompletionBlock：^ {
          * NSString的responseString;
          如果（！错误）{
              responseString = [要求responseString]
              self.appointmentsArray = [responseString JSONValue]              [self.appointmentsArrayTableView reloadData]; //我假设你想在一些视图中显示约会
          }其他{
              的NSLog（@错误：％@，错误）;
          }
      }];
      [要求setFailedBlock：^ {
          * NSString的responseString;
          如果（！错误）{
              responseString = [要求responseString]
          }其他{
              的NSLog（@错误：％@，错误）;
          }
      }];
      [请求startAsynchronous]
}
 

I'm trying to return a NSMutableArray from my block in my method, but when I add the line return [responseString JSONValue];, I get some compiler warnings.

- (NSMutableArray*)getTodayData:(NSDate*)today
{
        ASIFormDataRequest *request = [[[ASIFormDataRequest alloc] initWithURL:url] autorelease];
        [request setPostValue:[dateFormat stringFromDate:today] forKey:@"target_date"];
        NSError *error = [request error];

        [request setCompletionBlock:^{
            NSString *responseString;
            if (!error) {
                responseString = [request responseString];
                return [responseString JSONValue];
            } else {
                NSLog(@"error: %@", error);
            }
        }];
        [request setFailedBlock:^{
            NSString *responseString;
            if (!error) {
                responseString = [request responseString];
            } else {
                NSLog(@"error: %@", error);
            }
        }];
        [request startAsynchronous];
}

解决方案

The setCompletionBlock: and setFailedBlock: methods in ASIFormDataRequest do not accept blocks with a return value. You need to restructure your code so that there is no return value.

For example:

- (void)viewDidLoad
{
  [self getTodayData:self.datePicker.date];
}

- (void)getTodayData:(NSDate*)today
{
      self.appointmentsArray = [NSArray array]; // set it to an empty value now, so the table view displays nothing

      ASIFormDataRequest *request = [[[ASIFormDataRequest alloc] initWithURL:url] autorelease];
      [request setPostValue:[dateFormat stringFromDate:today] forKey:@"target_date"];
      NSError *error = [request error];

      [request setCompletionBlock:^{
          NSString *responseString;
          if (!error) {
              responseString = [request responseString];
              self.appointmentsArray = [responseString JSONValue];

              [self.appointmentsArrayTableView reloadData]; // I'm assuming you want to display the appointments in some view
          } else {
              NSLog(@"error: %@", error);
          }
      }];
      [request setFailedBlock:^{
          NSString *responseString;
          if (!error) {
              responseString = [request responseString];
          } else {
              NSLog(@"error: %@", error);
          }
      }];
      [request startAsynchronous];
}

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