是否有可能减少文本之间的差距,当把在一个UILabel多行?我们可以设置框架,字体大小和行数。我想减少标签中两行之间的差距。
当前回答
在UITextView或UILabel扩展中,添加这个函数:
我添加了一些代码来保持当前的带属性文本,如果您已经在视图中使用带属性字符串(而不是覆盖它们)。
func setLineHeight(_ lineHeight: CGFloat) {
guard let text = self.text, let font = self.font else { return }
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 1.0
paragraphStyle.lineHeightMultiple = lineHeight
paragraphStyle.alignment = self.textAlignment
var attrString:NSMutableAttributedString
if let attributed = self.attributedText {
attrString = NSMutableAttributedString(attributedString: attributed)
} else {
attrString = NSMutableAttributedString(string: text)
attrString.addAttribute(NSFontAttributeName, value: font, range: NSMakeRange(0, attrString.length))
}
attrString.addAttribute(NSParagraphStyleAttributeName, value:paragraphStyle, range:NSMakeRange(0, attrString.length))
self.attributedText = attrString
}
其他回答
在ios6中有另一个答案,那就是在标签上设置attributedText,使用NSAttributedString和适当的段落样式。关于NSAttributedString的行高,请参阅堆栈溢出答案:
NSAttributedString行高,对吗?
根据@Mike的回答,减少lineHeightMultiple是关键点。下面的例子,它很适合我:
NSString* text = label.text;
CGFloat textWidth = [text sizeWithAttributes:@{NSFontAttributeName: label.font}].width;
if (textWidth > label.frame.size.width) {
NSMutableParagraphStyle *paragraph = [[NSMutableParagraphStyle alloc] init];
paragraph.alignment = NSTextAlignmentCenter;
paragraph.lineSpacing = 1.0f;
paragraph.lineHeightMultiple = 0.75; // Reduce this value !!!
NSMutableAttributedString* attrText = [[NSMutableAttributedString alloc] initWithString:text];
[attrText addAttribute:NSParagraphStyleAttributeName value:paragraph range:NSMakeRange(0, text.length)];
label.attributedText = attrText;
}
这应该会有帮助。然后你可以将你的标签分配给故事板中的这个自定义类,并直接在属性中使用它的参数:
open class SpacingLabel : UILabel {
@IBInspectable open var lineHeight:CGFloat = 1 {
didSet {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 1.0
paragraphStyle.lineHeightMultiple = self.lineHeight
paragraphStyle.alignment = self.textAlignment
let attrString = NSMutableAttributedString(string: self.text!)
attrString.addAttribute(NSAttributedStringKey.font, value: self.font, range: NSMakeRange(0, attrString.length))
attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attrString.length))
self.attributedText = attrString
}
}
}
下面是UILabel的一个子类,它设置lineHeightMultiple并确保内在高度足够大,不会截断文本。
@IBDesignable
class Label: UILabel {
override var intrinsicContentSize: CGSize {
var size = super.intrinsicContentSize
let padding = (1.0 - lineHeightMultiple) * font.pointSize
size.height += padding
return size
}
override var text: String? {
didSet {
updateAttributedText()
}
}
@IBInspectable var lineHeightMultiple: CGFloat = 1.0 {
didSet {
updateAttributedText()
}
}
private func updateAttributedText() {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineHeightMultiple = lineHeightMultiple
attributedText = NSAttributedString(string: text ?? "", attributes: [
.font: font,
.paragraphStyle: paragraphStyle,
.foregroundColor: textColor
])
invalidateIntrinsicContentSize()
}
}
我找到了一种方法,你可以设置真实的行高(不是一个因素),它甚至在界面生成器中渲染。按照下面的说明做就可以了。代码是用Swift 4编写的。
步骤#1:创建一个名为DesignableLabel.swift的文件,并插入以下代码:
import UIKit
@IBDesignable
class DesignableLabel: UILabel {
@IBInspectable var lineHeight: CGFloat = 20 {
didSet {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.minimumLineHeight = lineHeight
paragraphStyle.maximumLineHeight = lineHeight
paragraphStyle.alignment = self.textAlignment
let attrString = NSMutableAttributedString(string: text!)
attrString.addAttribute(NSAttributedStringKey.font, value: font, range: NSRange(location: 0, length: attrString.length))
attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: attrString.length))
attributedText = attrString
}
}
}
步骤#2:将UILabel放入Storyboard/XIB中,并将其类设置为DesignableLabel。等待项目构建完成(构建必须成功!)。
步骤3:现在你应该在属性窗格中看到一个名为“Line Height”的新属性。只需设置您喜欢的值,您应该立即看到结果!