如何修改多行 UILabel
的行间距(行距)?
编辑:显然在 iOS 6 及以上版本中,NSAttributedString
可以实现这一点。不要使用 NSString
来设置标签的文本,而是创建一个 NSAttributedString
,在上面设置属性,然后将其作为标签的 .attributedText
设置。你想要的代码应该像这样:
NSMutableAttributedString* attrString = [[NSMutableAttributedString alloc] initWithString:@"Sample text"];
NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
[style setLineSpacing:24];
[attrString addAttribute:NSParagraphStyleAttributeName
value:style
range:NSMakeRange(0, strLength)];
uiLabel.attributedText = attrString;
NSAttributedString的旧属性字符串attributedStringWithString
可以实现同样的功能,但是现在已被弃用。
简短回答:你无法更改文本行之间的间距。要想实现这个功能,你需要创建一个子类UILabel
,并重写drawTextInRect
方法,创建多个标签,或使用不同的字体(也许是为特定行高编辑过的字体,详见Phillipe的回答)。
长篇回答:在印刷和在线世界中,文本行之间的空格称为"行间距"(与'heading'押韵,并来自几十年前使用的铅金属)。行间距是UIFont
的只读属性,在4.0版本中被弃用,由lineHeight
替代。据我所知,没有办法创建具有特定参数(如lineHeight
)的字体; 你可以获得系统字体和任何添加的自定义字体,但安装后不能调整它们。
UILabel
中也没有行间距参数。
对于UILabel
的行为,笔者不是特别满意,因此建议编写自己的子类或使用第三方库。这将使行为独立于字体选择,并成为最可重用的解决方案。
我希望UILabel
能够提供更多的灵活性,如果有人可以证明我是错误的,那将使我非常高兴!
从 iOS 6 开始,您可以在 UILabel 中设置一个带属性的字符串:
NSString *labelText = @"some text";
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:labelText];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
[paragraphStyle setLineSpacing:40];
[attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [labelText length])];
cell.label.attributedText = attributedString ;
AttributedString
会禁用标签的文本对齐功能,因此您需要将其添加到段落样式中。 - cyborg86pl从接口构建器:
通过编程:
Swift 4
使用标签扩展
extension UILabel {
func setLineSpacing(lineSpacing: CGFloat = 0.0, lineHeightMultiple: CGFloat = 0.0) {
guard let labelText = self.text else { return }
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = lineSpacing
paragraphStyle.lineHeightMultiple = lineHeightMultiple
let attributedString:NSMutableAttributedString
if let labelattributedText = self.attributedText {
attributedString = NSMutableAttributedString(attributedString: labelattributedText)
} else {
attributedString = NSMutableAttributedString(string: labelText)
}
// Line spacing attribute
attributedString.addAttribute(NSAttributedStringKey.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))
self.attributedText = attributedString
}
}
现在调用扩展函数
let label = UILabel()
let stringValue = "How to\ncontrol\nthe\nline spacing\nin UILabel"
// Pass value for any one argument - lineSpacing or lineHeightMultiple
label.setLineSpacing(lineSpacing: 2.0) . // try values 1.0 to 5.0
// or try lineHeightMultiple
//label.setLineSpacing(lineHeightMultiple = 2.0) // try values 0.5 to 2.0
或者使用标签实例(只需复制并执行此代码即可查看结果)
let label = UILabel()
let stringValue = "Set\nUILabel\nline\nspacing"
let attrString = NSMutableAttributedString(string: stringValue)
var style = NSMutableParagraphStyle()
style.lineSpacing = 24 // change line spacing between paragraph like 36 or 48
style.minimumLineHeight = 20 // change line spacing between each line like 30 or 40
// Line spacing attribute
attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value: style, range: NSRange(location: 0, length: stringValue.characters.count))
// Character spacing attribute
attrString.addAttribute(NSAttributedStringKey.kern, value: 2, range: NSMakeRange(0, attrString.length))
label.attributedText = attrString
Swift 3
let label = UILabel()
let stringValue = "Set\nUILabel\nline\nspacing"
let attrString = NSMutableAttributedString(string: stringValue)
var style = NSMutableParagraphStyle()
style.lineSpacing = 24 // change line spacing between paragraph like 36 or 48
style.minimumLineHeight = 20 // change line spacing between each line like 30 or 40
attrString.addAttribute(NSParagraphStyleAttributeName, value: style, range: NSRange(location: 0, length: stringValue.characters.count))
label.attributedText = attrString
我的解决方案是修补字体文件本身并明确修复其行高。
http://mbauman.net/geek/2009/03/15/minor-truetype-font-editing-on-a-mac/我必须修改'hhea'块中的'lineGap'、'ascender'和'descender'(如博客示例中所示)。
我找到最好的东西是:https://github.com/mattt/TTTAttributedLabel
这是UILabel的子类,所以你只需将其放入即可,然后更改行高:
myLabel.lineHeightMultiple = 0.85;
myLabel.leading = 2;
let label = UILabel()
let attributedText = NSMutableAttributedString(string: "Your string")
let paragraphStyle = NSMutableParagraphStyle()
//SET THIS:
paragraphStyle.lineSpacing = 4
//OR SET THIS:
paragraphStyle.lineHeightMultiple = 4
//Or set both :)
let range = NSMakeRange(0, attributedText.length)
attributedText.addAttributes([NSParagraphStyleAttributeName : paragraphStyle], range: range)
label.attributedText = attributedText
NSMutableAttributedString * attrString = [[NSMutableAttributedString alloc] initWithString:@"Your \nregular \nstring"];
NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
[style setLineSpacing:4];
[attrString addAttribute:NSParagraphStyleAttributeName
value:style
range:NSMakeRange(0, attrString.length)];
_label.attributedText = attrString;