ios - 长时间运行的解析操作正在主线程上执行似乎无法摆脱这个

Question

我收到长时间运行的解析操作错误。但我似乎不明白为什么。在选择一个选项时，这将打开一个 View Controller ，其中包含该选项的所有详细信息

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    // Check that a new transition has been requested to the DetailViewController and prepares for it
    if ([segue.identifier isEqualToString:@"TradeSend"]){

        // Capture the object (e.g. exam) the user has selected from the list
        NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
        PFObject *object = [self.objects objectAtIndex:indexPath.row];

        // Set destination view controller to DetailViewController to avoid the NavigationViewController in the middle (if you have it embedded into a navigation controller, if not ignore that part)
        //UINavigationController *nav = [segue destinationViewController];
        DMKDetailTradeFairViewController *detailViewController = (DMKDetailTradeFairViewController *) [segue destinationViewController];
        detailViewController.exam = object;
        NSLog(@"object details: %@",object);
    }
}

下一个 View Controller 打开时出现错误

- (void)viewDidLoad
{

    [_scroller setScrollEnabled:YES];
    [_scroller setContentSize:CGSizeMake(320, 1300)];

    self.compname.text = [self.exam objectForKey:@"name"];
    self.address1.text = [self.exam objectForKey:@"address1"];
    self.address2.text = [self.exam objectForKey:@"address2"];
    self.postcode.text = [self.exam objectForKey:@"postcode"];
    self.tel.text = [self.exam objectForKey:@"phone1"];
    self.email.text = [self.exam objectForKey:@"email"];
    self.NewName.text = [self.exam objectForKey:@"ContactName"];
    self.standnumber.text = [self.exam objectForKey:@"StandNumber"];
    self.details.text = [self.exam objectForKey:@"Description"];

    [[self.exam objectForKey:@"Logo"] getData];
    self.Logo.image = [[UIImage alloc] initWithData: [[self.exam objectForKey:@"Logo"] getData]];

    [[self.exam objectForKey:@"image1"] getData];
    self.image1.image = [[UIImage alloc] initWithData: [[self.exam objectForKey:@"image3"] getData]];

    [[self.exam objectForKey:@"image2"] getData];
    self.image2.image = [[UIImage alloc] initWithData: [[self.exam objectForKey:@"image2"] getData]];

    [[self.exam objectForKey:@"image3"] getData];
    self.image3.image = [[UIImage alloc] initWithData: [[self.exam objectForKey:@"image1"] getData]];


    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

预先感谢您的帮助

我已经在其中的 4 个上添加了 getDataInBackgroundWithBlock，但是另外 4 个不让我添加它，因为一些关于发送 void 的事情

这是我能做的

[[self.exam objectForKey:@"Logo"] getDataInBackgroundWithBlock:^(NSData *data, NSError *error) {
        self.Logo.image = [[UIImage alloc] initWithData:data];
    }];

    self.Logo.image = [[UIImage alloc] initWithData: [[self.exam objectForKey:@"Logo"] getData]];

    [[self.exam objectForKey:@"image1"] getDataInBackgroundWithBlock:^(NSData *data, NSError *error) {
        self.Logo.image = [[UIImage alloc] initWithData:data];
    }];

    self.image1.image = [[UIImage alloc] initWithData: [[self.exam objectForKey:@"image1"] getData]];

    [[self.exam objectForKey:@"image2"] getDataInBackgroundWithBlock:^(NSData *data, NSError *error) {
        self.Logo.image = [[UIImage alloc] initWithData:data];
    }];

    self.image2.image = [[UIImage alloc] initWithData: [[self.exam objectForKey:@"image2"] getData]];

    [[self.exam objectForKey:@"image3"] getDataInBackgroundWithBlock:^(NSData *data, NSError *error) {
        self.Logo.image = [[UIImage alloc] initWithData:data];
    }];

    self.image3.image = [[UIImage alloc] initWithData: [[self.exam objectForKey:@"image3"] getData]];

Answer 1

您走在正确的轨道上。不过，您应该这样做:

[[self.exam objectForKey:@"Logo"] getDataInBackgroundWithBlock:^(NSData *data, NSError *error) {
      self.Logo.image = [[UIImage alloc] initWithData:data];
}];

对于每张图片。该 block 以 NSData 格式返回数据，您当前未使用它。这样，您将使用 block 中的数据并在后台加载所有数据，而不会阻塞主线程。