Xcode - 如果語句保持UILabel顯示

Question

嘿，我需要幫助，似乎沒有工作的if語句。

基本上我有一個UILabel，顯示一個賽車系列的結果。現在如果該輪還沒有運行，結果不應該在那裏，也不會顯示UILabel。

我在標籤（不適用）中放入了一個'NA'的值，並在其上運行if語句來說明這個數據的結果是否等於NA，然後不打擾製作標籤。但無論如何，它會打印出「NA」數據。

這裏是我的代碼：

- (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; 

} 

現在我已成立了一個提示框，顯示物品的價值是視圖加載時，它的值是正確的，如果它已經運行，它顯示的值誰贏了，當它沒有運行時，它顯示值NA。

難道這是因爲UILabel設置爲numberofline = 2嗎？與某個角色返回什麼有關？

該標籤也位於滾動視圖內。

Answer 1

使用

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