我有一个UILabel，我想在顶部和底部添加空格。在限制最小高度的情况下，我将其修改为:
为了做到这一点，我使用了:
override func drawTextInRect(rect: CGRect) {
var insets: UIEdgeInsets = UIEdgeInsets(top: 0.0, left: 10.0, bottom: 0.0, right: 10.0)
super.drawTextInRect(UIEdgeInsetsInsetRect(rect, insets))
}
但我必须找到不同的方法，因为如果我写了超过两行，问题是一样的:
当前回答
使用UILabel扩展的Swift 5示例
使用下面的代码，设置你的边距就像label. setmargin(15)一样简单。
extension UILabel {
func setMargins(_ margin: CGFloat = 10) {
if let textString = self.text {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.firstLineHeadIndent = margin
paragraphStyle.headIndent = margin
paragraphStyle.tailIndent = -margin
let attributedString = NSMutableAttributedString(string: textString)
attributedString.addAttribute(.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: attributedString.length))
attributedText = attributedString
}
}
}
其他回答
斯威夫特 4+
class EdgeInsetLabel: UILabel {
var textInsets = UIEdgeInsets.zero {
didSet { invalidateIntrinsicContentSize() }
}
override func textRect(forBounds bounds: CGRect, limitedToNumberOfLines numberOfLines: Int) -> CGRect {
let textRect = super.textRect(forBounds: bounds, limitedToNumberOfLines: numberOfLines)
let invertedInsets = UIEdgeInsets(top: -textInsets.top,
left: -textInsets.left,
bottom: -textInsets.bottom,
right: -textInsets.right)
return textRect.inset(by: invertedInsets)
}
override func drawText(in rect: CGRect) {
super.drawText(in: rect.inset(by: textInsets))
}
}
用法:
let label = EdgeInsetLabel()
label.textInsets = UIEdgeInsets(top: 2, left: 6, bottom: 2, right: 6)
斯威夫特3
import UIKit
class PaddingLabel: UILabel {
@IBInspectable var topInset: CGFloat = 5.0
@IBInspectable var bottomInset: CGFloat = 5.0
@IBInspectable var leftInset: CGFloat = 5.0
@IBInspectable var rightInset: CGFloat = 5.0
override func drawText(in rect: CGRect) {
let insets = UIEdgeInsets(top: topInset, left: leftInset, bottom: bottomInset, right: rightInset)
super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))
}
override var intrinsicContentSize: CGSize {
get {
var contentSize = super.intrinsicContentSize
contentSize.height += topInset + bottomInset
contentSize.width += leftInset + rightInset
return contentSize
}
}
}
objective - c
基于Tai Le的回答，它在一个Interface Builder Designable中实现了这个特性，下面是Objective-C版本。
把这个放在YourLabel.h文件中:
@interface YourLabel : UILabel
@property IBInspectable CGFloat topInset;
@property IBInspectable CGFloat bottomInset;
@property IBInspectable CGFloat leftInset;
@property IBInspectable CGFloat rightInset;
@end
这个会放在yourlabel。m文件中:
IB_DESIGNABLE
@implementation YourLabel
#pragma mark - Super
- (instancetype)initWithCoder:(NSCoder *)aDecoder {
self = [super initWithCoder:aDecoder];
if (self) {
self.topInset = 0;
self.bottomInset = 0;
self.leftInset = 0;
self.rightInset = 0;
}
return self;
}
- (void)drawTextInRect:(CGRect)rect {
UIEdgeInsets insets = UIEdgeInsetsMake(self.topInset, self.leftInset, self.bottomInset, self.rightInset);
[super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];
}
- (CGSize)intrinsicContentSize {
CGSize size = [super intrinsicContentSize];
return CGSizeMake(size.width + self.leftInset + self.rightInset,
size.height + self.topInset + self.bottomInset);
}
@end
然后，在XIB文件或故事板中指定类后，您可以直接在Interface Builder中修改YourLabel嵌入，嵌入的默认值为零。
我在任何地方都没有看到这个答案。我的技巧是在标签上设置宽度限制，并在设置标签文本时调整宽度。
self.myLabel.text = myString;
UIFont * const font = [UIFont systemFontOfSize:17 weight:UIFontWeightRegular]; // Change to your own label font.
CGSize const size = CGSizeMake(INFINITY, 18); // 18 is height of label.
CGFloat const textWidth = [myString boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName: font} context:nil].size.width;
self.myLabelWidthConstraint.constant = textWidth + 20; // 10 padding on each side. Also, set text alignment to centre.
