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:
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。
斯威夫特4
易于使用的解决方案,可用于项目中的所有UILabel子。
例子:
let label = UILabel()
label.<Do something>
label.padding = UIEdgeInsets(top: 0, left: 16, bottom: 0, right: 0)
UILabel扩展
import UIKit
extension UILabel {
private struct AssociatedKeys {
static var padding = UIEdgeInsets()
}
public var padding: UIEdgeInsets? {
get {
return objc_getAssociatedObject(self, &AssociatedKeys.padding) as? UIEdgeInsets
}
set {
if let newValue = newValue {
objc_setAssociatedObject(self, &AssociatedKeys.padding, newValue as UIEdgeInsets?, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC)
}
}
}
override open func draw(_ rect: CGRect) {
if let insets = padding {
self.drawText(in: rect.inset(by: insets))
} else {
self.drawText(in: rect)
}
}
override open var intrinsicContentSize: CGSize {
guard let text = self.text else { return super.intrinsicContentSize }
var contentSize = super.intrinsicContentSize
var textWidth: CGFloat = frame.size.width
var insetsHeight: CGFloat = 0.0
var insetsWidth: CGFloat = 0.0
if let insets = padding {
insetsWidth += insets.left + insets.right
insetsHeight += insets.top + insets.bottom
textWidth -= insetsWidth
}
let newSize = text.boundingRect(with: CGSize(width: textWidth, height: CGFloat.greatestFiniteMagnitude),
options: NSStringDrawingOptions.usesLineFragmentOrigin,
attributes: [NSAttributedString.Key.font: self.font], context: nil)
contentSize.height = ceil(newSize.size.height) + insetsHeight
contentSize.width = ceil(newSize.size.width) + insetsWidth
return contentSize
}
}
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)