ios - 如何在 UILabel 的末尾添加更多按钮？

Question

我已经研究了很长时间了。我需要通过单击位于 UILabel 文本末尾的按钮来展开和折叠 UILabel 文本。

我觉得我试过了我已经使用 VSWordDetector 来检测 UILabel 的哪个单词被点击了，但它没有给出正确的单词被点击。

Answer 1

我建议你只使用 UIButton 没有可见框架 titleLabel.text @"..." 或 @"▼ “。因此，例如，您有一个字符串 @"Some long long, really long string which couldn't be presented in one line"。然后为 UILabel 文本取一个子字符串，并在您的标签右侧放置一个上述按钮。为 ▼-buuton 添加一个操作来更新 label.text 并隐藏按钮。代码片段:

@interface YourClass

@property (strong, nonatomic) UILabel* longStringLabel;
@property (strong, nonatomic) UIButton* moreButton;
@property (strong, nonatomic) NSString* text;

@end

@implementation YourClass

// Some method, where you add subviews, for example viewDidLoad
{
// ...
    self.longStringLabel.frame = CGRectMake(0, 0, 100, 44);
    [self addSubview:self.longStringLabel];

    self.moreButton.frame = CGRectMake(CGRectGetMaxX(self.longStringLabel.frame), 0, 20, 44);
    [self addSubview:self.moreButton];
// ...
}

- (UILabel*)longStringLabel
{
    if (!_longStringLabel)
    {
        _longStringLabel = [UILabel new];
        _longStringLabel.lineBreakMode = NSLineBreakByTruncatingTail;
    }

    return _longStringLabel;
}

- (UIButton*)moreButton
{
    if (!_moreButton)
    {
        _moreButton = [UIButton buttonWithType:UIButtonTypeCustom];
        _moreButton.titleLabel.text = @"▼";
        [_moreButton addTarget:self action:@selector(moreButtonDidTap:) forControlEvents:UIControlEventTouchUpInside];
    }
    return _moreButton;
}

- (void)moreButtonDidTap:(UIButton*)sender
{
    self.longStringLabel.frame = [self.text boundingRectWithSize:CGSizeMake(self.longStringLabel.frame.size.width + self.moreButton.frame.size.width, 100)
                                                         options:NSStringDrawingUsesLineFragmentOrigin
                                                      attributes:@{ NSFontAttributeName : self.longStringLabel.font }
                                                         context:nil];
    self.longStringLabel.text = self.text;

    self.moreButton.hidden = YES;
}

@end