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
如果你不想或需要在Storyboard中使用@IBInspectable / @IBDesignable UILabel(我认为那些渲染太慢了)，那么使用UIEdgeInsets而不是4个不同的cgfloat会更干净。
Swift 4.2的代码示例:
class UIPaddedLabel: UILabel {
var padding = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
public override func drawText(in rect: CGRect) {
super.drawText(in: rect.inset(by: padding))
}
public override var intrinsicContentSize: CGSize {
let size = super.intrinsicContentSize
return CGSize(width: size.width + padding.left + padding.right,
height: size.height + padding.top + padding.bottom)
}
}
其他回答
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
}
}
}
斯威夫特5
在layoutSubviews()方法上，更改UILabel的插入，如下所示。
override func layoutSubviews() {
super.layoutSubviews()
label.frame = label.frame.inset(by: UIEdgeInsets(top: 5, left: 10, bottom: 5, right: 10))
}
类似于其他答案，但使用func类来动态地设置填充:
class UILabelExtendedView: UILabel
{
var topInset: CGFloat = 4.0
var bottomInset: CGFloat = 4.0
var leftInset: CGFloat = 8.0
var rightInset: CGFloat = 8.0
override func drawText(in rect: CGRect)
{
let insets: UIEdgeInsets = UIEdgeInsets(top: topInset, left: leftInset, bottom: bottomInset, right: rightInset)
super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))
}
override public var intrinsicContentSize: CGSize
{
var contentSize = super.intrinsicContentSize
contentSize.height += topInset + bottomInset
contentSize.width += leftInset + rightInset
return contentSize
}
func setPadding(top: CGFloat, left: CGFloat, bottom: CGFloat, right: CGFloat){
self.topInset = top
self.bottomInset = bottom
self.leftInset = left
self.rightInset = right
let insets: UIEdgeInsets = UIEdgeInsets(top: top, left: left, bottom: bottom, right: right)
super.drawText(in: UIEdgeInsetsInsetRect(self.frame, insets))
}
}
如果你想使用UILabel
class UILabel : UIKit.UILabel {
var insets = 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: -insets.top,
left: -insets.left,
bottom: -insets.bottom,
right: -insets.right)
return textRect.inset(by: invertedInsets)
}
override func drawText(in rect: CGRect) {
super.drawText(in: rect.inset(by: insets))
}
}
