Question

我正在尝试在UINavigationBar中设置两行标签。当我执行以下操作时，它只显示一行（换行符之前的部分）。

NSString *title = @"First line of title is bigger\nSecond line of title is smaller";
NSDictionary *attribute1 = @{NSForegroundColorAttributeName: [UIColor colorWithRed:148/255.0f green:147/255.0f blue:147/255.0f alpha:1],
                             NSFontAttributeName: [UIFont boldSystemFontOfSize: 14.0f]};
NSDictionary *attribute2 = @{NSForegroundColorAttributeName: [UIColor colorWithRed:148/255.0f green:147/255.0f blue:147/255.0f alpha:1],
                             NSFontAttributeName: [UIFont boldSystemFontOfSize: 10.0f]};
const NSRange line1Range = {0, 29};
const NSRange line2Range = {31, 30};

NSMutableAttributedString *attributedText =[[NSMutableAttributedString alloc] initWithString:title];
[attributedText setAttributes: attribute1 range:line1Range];
[attributedText setAttributes: attribute2 range:line2Range];

UILabel *label = [[UILabel alloc] init];
label.attributedText=attributedText;
self.navigationItem.titleView = label;
[self.navigationItem.titleView sizeToFit];

为了比较，以下显示两行。以下仅供比较。顶级版本是我需要的。

UILabel *label = [[UILabel alloc] init];
label.backgroundColor = [UIColor clearColor];
label.numberOfLines = 2;
label.font = [UIFont boldSystemFontOfSize: 14.0f];
label.textColor = [UIColor colorWithRed:148/255.0f green:147/255.0f blue:147/255.0f alpha:1];
label.text = @"First line of title is bigger\nSecond line of title is smaller";

self.navigationItem.titleView = label;
[self.navigationItem.titleView sizeToFit];

帮助顶级版本正常运行的任何帮助？

Answer 1

似乎在 label.sizeToFit()之前调用self.navigationItem.titleView = label 会正确显示NSAttributedString标题。

（Swift，iOS8.1，XCode 6.1.1）

Answer 2

简单的问题，简单的解决方案。即使您使用的是attributionText而不是text，仍然需要：

label.numberOfLines = 0;

UINavigationBar中的AttributedString不显示两行文本

2 个答案: