UIRefreshControl属性标题多行

Question

是否可以在UIRefreshControl标题中使用多行？每当我将\ n添加到NSAttributedString时，只会显示第一行。我试图设置标题，然后在下一行设置更多文字。那么有一种解决方法是在UIRefreshControl中使用两行文本吗？

这是当前的代码，其中只有＆＃34; Title Here＆＃34;显示：

self.refreshControl = [[UIRefreshControl alloc] init];

NSString *title = @"Title Here";
NSString *subText = @"Subtext Here";
NSMutableAttributedString *attString=[[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"%@\n%@",title,subText]];

[attString addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Helvetica" size:20.0f] range:NSMakeRange(0, [title length])];
[attString addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Helvetica" size:14.0f] range:NSMakeRange([title length],[subText length])];

[attString addAttribute:NSForegroundColorAttributeName value:[UIColor blackColor] range:NSMakeRange(0, [title length])];
[attString addAttribute:NSForegroundColorAttributeName value:[UIColor lightGrayColor] range:NSMakeRange([title length], [subText length])];

self.refreshControl.attributedTitle = attString;

Answer 1

这是 棘手的 方法：在UIRefreshControl中找到UILabel并设置numberOfLines = 0.

UILabel *titleLabel = [[[[self.refreshControl subviews] firstObject] subviews] lastObject];
if (titleLabel) {
    titleLabel.numberOfLines = 0;

    NSString title = @"Pull to Refresh.\nUpdated Time: 09:30"; // \n for new line.
    self.refreshControl.attributedTitle = [[NSAttributedString alloc] initWithString:title];
}

Answer 2

这段代码可以使用

NSString *title = @"Title Here";
NSString *subText = @"Subtext Here";

NSMutableAttributedString *titleAttString =  [[NSMutableAttributedString alloc] initWithString:title];
NSMutableAttributedString *subTitleAttString =  [[NSMutableAttributedString alloc] initWithString:subText];

[titleAttString addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Helvetica" size:20.0f] range:NSMakeRange(0, [title length])];
[subTitleAttString addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Helvetica" size:14.0f] range:NSMakeRange(0,[subTitle length])];

[titleAttString addAttribute:NSForegroundColorAttributeName value:[UIColor blackColor] range:NSMakeRange(0, [title length])];
[subTitleAttString addAttribute:NSForegroundColorAttributeName value:[UIColor lightGrayColor] range:NSMakeRange(0, [subTitle length])];

[titleAttString appendAttributedString:subTitleAttString];

self.refreshControl.attributedTitle = titleAttString;

Answer 3

技巧是将“刷新控制器”的UILable属性更改为零。 hack是我们必须通过子视图找到标签，并在其中找到子对象，如下所示。

这是Swift版本

    if let refreshLabel = refreshControl?.subviews.first?.subviews.last as? UILabel {
            refreshLabel.numberOfLines = 0
    }

这是完整的代码示例

private var marketRefreshController = UIRefreshControl()
private var lastUpdatedDate = Date()

override func viewDidLoad() {
    super.viewDidLoad()
    tableView.refreshControl = marketRefreshController
    if let refreshLabel = refreshControl?.subviews.first?.subviews.last as? UILabel {
        refreshLabel.numberOfLines = 0
    }
    marketRefreshController.addTarget(self, action: #selector(refreshMarketData), for: .valueChanged)
    marketRefreshController.tintColor = UIColor.blue
    let textAttributes = [NSAttributedString.Key.font: UIFont.appSubTitle,
                          NSAttributedString.Key.foregroundColor: UIColor.blue]
    let timeSinceLastUpdate = lastUpdatedDate.timeAgoSinceNow // Date Sting Converter Helper Method
    let displayString = "Fetching Market Data ... \n Last Updated: \(timeSinceLastUpdate)"
    marketRefreshController.attributedTitle = NSAttributedString(string: displayString,
                                                                 attributes: textAttributes)
    tableView.addSubview(marketRefreshController)
}

预期输出应为-