Question

我试图以编程方式添加UILabel（我已经用IB完成了它并且它有效）。但我无法找出它为什么没有出现..我已经编程添加了一个按钮，工作得很好。我想按钮用随机引号更新标签。怎么了？

.H-文件：

@interface SecondViewController : UIViewController
{
    NSArray *citatDatabas;

}

@property (weak, nonatomic) IBOutlet UIButton *helloButton;
@property (weak, nonatomic) IBOutlet UIButton *citatKnapp;
@property (weak, nonatomic) IBOutlet UILabel *label1;

- (void)helloButtonPressed;
- (IBAction)citatKnappPressed:(id)sender;

@end

实现：

@implementation SecondViewController
@synthesize helloButton, citatKnapp, label1;

- (void)loadView {
    [super loadView]; 
citatDatabas = [NSArray arrayWithObjects:
                    [NSString stringWithFormat:@"%@", @"People ask me, would you rather be feared or loved, um easy, I want people to be afriad of how much they love me - Michael Scott" ],
                    [NSString stringWithFormat:@"%@", @"You miss 100% of all the shoots you dont take - Wayne Greatsky - Michael Scott" ],
                    [NSString stringWithFormat:@"%@", @"DONT PANIC - hitchhiker's guide to the galaxy" ],
                    [NSString stringWithFormat:@"%@", @"Give someone a mask and they'll show their true face - Oscar Wilde" ],
                    [NSString stringWithFormat:@"%@", @"Given enough time, hydrogen starts to wonder where it came from, and where it is going" ],
                    [NSString stringWithFormat:@"%@", @"You have just begun reading the sentence you just finished reading" ],
                    nil];



    self.citatKnapp = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    self.citatKnapp.frame = CGRectMake(98, 162, 124, 37);
    [self.citatKnapp setTitle:@"Tryck för citat" forState:UIControlStateNormal];
    [self.citatKnapp addTarget:self action:@selector(citatKnappPressed:)     forControlEvents:UIControlEventTouchUpInside];

    self.citatKnapp.autoresizingMask = UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin;

    [self.view addSubview:self.citatKnapp];

    self.label1 = [[UILabel alloc]initWithFrame:CGRectMake(20, 71, 200, 83)];

    self.label1.frame = CGRectMake(20, 71, 200, 83);
    self.label1.text = @"hej";
    self.label1.backgroundColor = [UIColor greenColor];
    [self.view addSubview:self.label1];


}

- (IBAction)citatKnappPressed:(id)sender{

    self.label1.text = [citatDatabas objectAtIndex:
                  (random() % [citatDatabas count])];
}

@end

Answer 1

您的标签已发布，请使用@property (strong, nonatomic) IBOutlet UILabel *label1;

如果在分配label1后在任何一行上设置了断点，您将看到label1为nil

Answer 2

在loadView中，您的视图未初始化。它是通过XIB / StoryBoard连接的吗？

如果没有，

只需将您的视图初始化为方法的第一行，即为其添加标签

self.view = [[UIView alloc]initWithFrame:CGRectMake(0,0,320,480)];

然后写下你剩下的代码

UILabel没有显示

2 个答案: