记录 UIButton titleLabel 显示 CALayer...而不是字符串

Question

我正在尝试获取 UIButton 的 titleLabel 字符串，但它记录为 CALayer...有什么建议吗？

//ADD TWT BUTTON
    twitter_share = [[UIButton alloc] initWithFrame:CGRectMake(200, 44, 29, 28)];
    twitter_share.backgroundColor = [UIColor clearColor];
    [twitter_share setBackgroundImage:[UIImage imageNamed:@"btn_annotation_share_twitter.png"] forState:UIControlStateNormal];
    twitter_share.titleLabel.hidden = YES;
    twitter_share.titleLabel.alpha = 0;
    twitter_share.tag = 20;
    [twitter_share setTitle:@"test!" forState:UIControlStateNormal];

    UITapGestureRecognizer *tap_twt = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinButtonTap:)];
    tap_twt.numberOfTapsRequired = 1;
    [twitter_share addGestureRecognizer:tap_twt];
    [tap_twt release];

    [annotationView addSubview:twitter_share];


- (void) handlePinButtonTap:(UITapGestureRecognizer *)gestureRecognizer {
    UIButton *btn = (UIButton *) gestureRecognizer.view;
    MKAnnotationView *av = (MKAnnotationView *)[btn superview];
    id<MKAnnotation> ann = av.annotation;
    NSLog(@"handlePinButtonTap: ann.title=%@", ann.title);

    NSString *testBtn = [NSString stringWithFormat:@"%@", [btn titleLabel]];

    NSLog(@"handlePinButtonTap: btn title=%@", testBtn);
    }

日志：

handlePinButtonTap: btn title=<UIButtonLabel: 0x70a14d0; frame = (0 3; 29 22); text = 'test!'; clipsToBounds = YES; alpha = 0; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x70a6930>>

Answer 1

这看起来不错，尽管您似乎对 -titleLabel 返回的内容有误解。

-titleLabel 返回一个 UILabel 实例 ->要检索 UILabel 中包含的文本字符串，您必须调用 -text getter。

Answer 2

您一定在某个地方出现了双重释放错误，这意味着您的 title 字符串已被过早释放，并且其内存已被另一个对象（CALayer）占用。搜索 NSZombieEnabled 或仅搜索 xcode僵尸，您应该能够打开僵尸检测，这将为您提供更多信息。