Question

嘿，我需要一个似乎不起作用的if语句的帮助。

基本上我有一个显示赛车系列结果的UILabel。现在如果那轮尚未运行，结果不应该在那里，也不会显示UILabel。

我在标签中放置了一个'NA'值（不适用），并在其上运行if语句，说明该数据的结果是否等于NA，然后不打扰制作标签。但无论如何它都会使它打印出来的数据“NA”。

这是我的代码：

- (void)viewDidLoad {

    // Create the scroll view for this view
    scrollView = [[UIScrollView alloc] initWithFrame:self.view.frame];
    scrollView.contentSize = CGSizeMake(320, 220);
    [scrollView setFrame:CGRectMake(0, 180, 320, 188)];

    // Create all the non-changing labels
    UILabel *date_title = [[UILabel alloc] initWithFrame:scrollView.bounds];
    date_title.textColor = [UIColor whiteColor];
    date_title.text = @"Event date:";
    date_title.font = [UIFont boldSystemFontOfSize:12];
    [date_title setBackgroundColor:[UIColor clearColor]];
    [date_title setFrame:CGRectMake(10, 35, 100, 12)];
    [scrollView addSubview:date_title];
    [date_title release];

    UILabel *direction_title = [[UILabel alloc] initWithFrame:scrollView.bounds];
    direction_title.textColor = [UIColor whiteColor];
    direction_title.text = @"Direction:";
    direction_title.font = [UIFont boldSystemFontOfSize:12];
    [direction_title setBackgroundColor:[UIColor clearColor]];
    [direction_title setFrame:CGRectMake(10, 55, 100, 12)];
    [scrollView addSubview:direction_title];
    [direction_title release];

    UILabel *tracklength_title = [[UILabel alloc] initWithFrame:scrollView.bounds];
    tracklength_title.textColor = [UIColor whiteColor];
    tracklength_title.text = @"Track Length:";
    tracklength_title.font = [UIFont boldSystemFontOfSize:12];
    [tracklength_title setBackgroundColor:[UIColor clearColor]];
    [tracklength_title setFrame:CGRectMake(10, 75, 100, 12)];
    [scrollView addSubview:tracklength_title];
    [tracklength_title release];

    UILabel *winner2010_title = [[UILabel alloc] initWithFrame:scrollView.bounds];
    winner2010_title.textColor = [UIColor whiteColor];
    winner2010_title.text = @"2010 Winners";
    winner2010_title.font = [UIFont boldSystemFontOfSize:12];
    [winner2010_title setBackgroundColor:[UIColor clearColor]];
    [winner2010_title setFrame:CGRectMake(10, 105, 300, 12)];
    [scrollView addSubview:winner2010_title];
    [winner2010_title release];

    winner2011_title = [[UILabel alloc] initWithFrame:scrollView.bounds];
    winner2011_title.textColor = [UIColor whiteColor];
    winner2011_title.font = [UIFont boldSystemFontOfSize:12];
    [winner2011_title setBackgroundColor:[UIColor clearColor]];
    [winner2011_title setFrame:CGRectMake(10, 160, 300, 12)];
    [scrollView addSubview:winner2011_title];
    [winner2011_title release];

    // Do the labels for the round_name
    name = [[UILabel alloc] initWithFrame:scrollView.bounds];
    name.textColor = [UIColor whiteColor];
    name.font = [UIFont boldSystemFontOfSize:16];
    [name setBackgroundColor:[UIColor clearColor]];
    [name setFrame:CGRectMake(10, 10, 280, 16)];
    [scrollView addSubview:name];
    [name release];

    // Do the labels for the round_date
    dates = [[UILabel alloc] initWithFrame:scrollView.bounds];
    dates.textColor = [UIColor whiteColor];
    dates.font = [UIFont systemFontOfSize:12];
    [dates setBackgroundColor:[UIColor clearColor]];
    [dates setFrame:CGRectMake(110, 35, 200, 12)];
    [scrollView addSubview:dates];
    [dates release];

    // Do the labels for the round_direction
    direction = [[UILabel alloc] initWithFrame:scrollView.bounds];
    direction.textColor = [UIColor whiteColor];
    direction.font = [UIFont systemFontOfSize:12];
    [direction setBackgroundColor:[UIColor clearColor]];
    [direction setFrame:CGRectMake(110, 55, 200, 12)];
    [scrollView addSubview:direction];
    [direction release];

    // Do the labels for the round_track_length
    track_length = [[UILabel alloc] initWithFrame:scrollView.bounds];
    track_length.textColor = [UIColor whiteColor];
    track_length.font = [UIFont systemFontOfSize:12];
    [track_length setBackgroundColor:[UIColor clearColor]];
    [track_length setFrame:CGRectMake(110, 75, 200, 12)];
    [scrollView addSubview:track_length];
    [track_length release];

    // Do the labels for the 2010 winners
    winner2010 = [[UILabel alloc] initWithFrame:scrollView.bounds];
    winner2010.textColor = [UIColor whiteColor];
    winner2010.font = [UIFont systemFontOfSize:12];
    winner2010.numberOfLines = 0;
    [winner2010 setBackgroundColor:[UIColor clearColor]];
    [winner2010 setFrame:CGRectMake(10, 120, 300, 30)];
    [scrollView addSubview:winner2010];
    [winner2010 release];

    // Do the labels for the 2011 winners
    winner2011 = [[UILabel alloc] initWithFrame:scrollView.bounds];
    winner2011.textColor = [UIColor whiteColor];
    winner2011.font = [UIFont systemFontOfSize:12];
    winner2011.numberOfLines = 0;
    [winner2011 setBackgroundColor:[UIColor clearColor]];
    [winner2011 setFrame:CGRectMake(10, 175, 300, 30)];
    [scrollView addSubview:winner2011];
    [winner2011 release];

    // Add the content to the main scrollview
    [self.view addSubview:scrollView];
    [scrollView release];

}


- (void)viewDidAppear:(BOOL)animated {

    if(![round_2011_winner isEqualToString:@"NA"]){
        winner2011_title.text = @"2011 Winners";
        winner2011.text = round_2011_winner;
    }

    name.text = round_name;
    dates.text = round_date;
    direction.text = round_direction;
    track_length.text = round_track_length;
    winner2010.text = round_2010_winner;

}

现在我已经设置了一个警告框来显示视图加载时的值是什么，它的值是否正确，如果它已经运行，它会显示谁赢了的值，以及它何时没有运行，它显示值NA。

这可能是因为UILabel设置为numberofline = 2吗？与角色回归有什么关系？

标签也在滚动视图中。

Answer 1

尝试使用

if (![round_2011_winner isEqualToString:@"NA"]) {
    ...
}

Xcode - 如果语句保持UILabel显示

1 个答案: