Xcode 6.1.1 Swift扩展解决方案。

文件名可以是"UILabel+AddInsetMargin.swift":

import UIKit

extension UILabel
{
    public override func drawRect(rect: CGRect)
    {
        self.drawTextInRect(UIEdgeInsetsInsetRect(rect, UIEdgeInsets(top: 0, left: 5, bottom: 0, right: 5)))
    }
}

回收钢铁的答案的Swift版本+ intrinsizeContentSize()。

它支持一个更传统的设置insets为其他视图对象的insets，同时能够设置insets在接口生成器，即insets设置像这样编程:

label.insets = UIEdgeInsetsMake(0, 0, 5, 0)

如果有任何错误，请告诉我。

斯威夫特5

@IBInspectable var topInset: CGFloat = 0.0
@IBInspectable var leftInset: CGFloat = 0.0
@IBInspectable var bottomInset: CGFloat = 0.0
@IBInspectable var rightInset: CGFloat = 0.0

var insets: UIEdgeInsets {
    get {
        return UIEdgeInsets(top: topInset, left: leftInset, bottom: bottomInset, right: rightInset)
    }
    set {
        topInset = newValue.top
        leftInset = newValue.left
        bottomInset = newValue.bottom
        rightInset = newValue.right
    }
}

override func drawText(in rect: CGRect) {
    super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))
}

override func sizeThatFits(_ size: CGSize) -> CGSize {
    var adjSize = super.sizeThatFits(size)
    adjSize.width += leftInset + rightInset
    adjSize.height += topInset + bottomInset
    
    return adjSize
}

override var intrinsicContentSize: CGSize {
    var contentSize = super.intrinsicContentSize
    contentSize.width += leftInset + rightInset
    contentSize.height += topInset + bottomInset
    
    return contentSize
}

斯威夫特4.2

@IBDesignable class InsetLabel: UILabel {
    @IBInspectable var topInset: CGFloat = 0.0
    @IBInspectable var leftInset: CGFloat = 0.0
    @IBInspectable var bottomInset: CGFloat = 0.0
    @IBInspectable var rightInset: CGFloat = 0.0
    
    var insets: UIEdgeInsets {
        get {
            return UIEdgeInsetsMake(topInset, leftInset, bottomInset, rightInset)
        }
        set {
            topInset = newValue.top
            leftInset = newValue.left
            bottomInset = newValue.bottom
            rightInset = newValue.right
        }
    }
    
    override func drawText(in rect: CGRect) {
        super.drawText(in: rect.inset(by: insets))
    }
    
    override func sizeThatFits(_ size: CGSize) -> CGSize {
        var adjSize = super.sizeThatFits(size)
        adjSize.width += leftInset + rightInset
        adjSize.height += topInset + bottomInset
        
        return adjSize
    }
    
    override var intrinsicContentSize: CGSize {
        var contentSize = super.intrinsicContentSize
        contentSize.width += leftInset + rightInset
        contentSize.height += topInset + bottomInset
        
        return contentSize
    }
}

斯威夫特3

@IBDesignable class InsetLabel: UILabel {
    @IBInspectable var topInset: CGFloat = 0.0
    @IBInspectable var leftInset: CGFloat = 0.0
    @IBInspectable var bottomInset: CGFloat = 0.0
    @IBInspectable var rightInset: CGFloat = 0.0
    
    var insets: UIEdgeInsets {
        get {
            return UIEdgeInsetsMake(topInset, leftInset, bottomInset, rightInset)
        }
        set {
            topInset = newValue.top
            leftInset = newValue.left
            bottomInset = newValue.bottom
            rightInset = newValue.right
        }
    }
    
    override func drawText(in rect: CGRect) {
        super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))
    }
    
    override func sizeThatFits(_ size: CGSize) -> CGSize {
        var adjSize = super.sizeThatFits(size)
        adjSize.width += leftInset + rightInset
        adjSize.height += topInset + bottomInset
        
        return adjSize
    }
    
    override var intrinsicContentSize: CGSize {
        var contentSize = super.intrinsicContentSize
        contentSize.width += leftInset + rightInset
        contentSize.height += topInset + bottomInset
        
        return contentSize
    }
}

斯威夫特2.2

@IBDesignable class InsetLabel: UILabel {
    @IBInspectable var topInset: CGFloat = 0.0
    @IBInspectable var leftInset: CGFloat = 0.0
    @IBInspectable var bottomInset: CGFloat = 0.0
    @IBInspectable var rightInset: CGFloat = 0.0
    
    var insets: UIEdgeInsets {
        get {
            return UIEdgeInsetsMake(topInset, leftInset, bottomInset, rightInset)
        }
        set {
            topInset = newValue.top
            leftInset = newValue.left
            bottomInset = newValue.bottom
            rightInset = newValue.right
        }
    }
        
    override func drawTextInRect(rect: CGRect) {
        super.drawTextInRect(UIEdgeInsetsInsetRect(rect, insets))
    }
        
    override func sizeThatFits(size: CGSize) -> CGSize {
        var adjSize = super.sizeThatFits(size)
        adjSize.width += leftInset + rightInset
        adjSize.height += topInset + bottomInset
        
        return adjSize
    }
    
    override func intrinsicContentSize() -> CGSize {
        var contentSize = super.intrinsicContentSize()
        contentSize.width += leftInset + rightInset
        contentSize.height += topInset + bottomInset
        
        return contentSize
    }
}

也许你可以试试这段代码

CGRect frame = btn.titleLabel.frame;
int indent = 20;
int inset = 20;
[btn.titleLabel setFrame:CGRectMake(frame.origin.x+inset,frame.origin.y,frame.size.width+indent,frame.size.height)];

这适用于多行标签:

class PaddedLabel: UILabel {
    var verticalPadding: CGFloat = 0
    var horizontalPadding: CGFloat = 0

    override func drawText(in rect: CGRect) {
        let insets = UIEdgeInsets(top: verticalPadding, left: horizontalPadding, bottom: verticalPadding, right: horizontalPadding)
        super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))
    }

    override var intrinsicContentSize: CGSize {
        get {
            let textWidth = super.intrinsicContentSize.width - horizontalPadding * 2
            let textHeight = sizeThatFits(CGSize(width: textWidth, height: .greatestFiniteMagnitude)).height
            let width = textWidth + horizontalPadding * 2
            let height = textHeight + verticalPadding * 2
            return CGSize(width: frame.width, height: height)
        }
    }
}

为UILabel添加填充的最佳方法是子类化UILabel并添加一个edgeInsets属性。然后设置所需的插图，标签将相应地绘制。

OSLabel.h

#import <UIKit/UIKit.h>

@interface OSLabel : UILabel

@property (nonatomic, assign) UIEdgeInsets edgeInsets;

@end

OSLabel.m

#import "OSLabel.h"

@implementation OSLabel

- (id)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    if (self) {
        self.edgeInsets = UIEdgeInsetsMake(0, 0, 0, 0);
    }
    return self;
}

- (void)drawTextInRect:(CGRect)rect {
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, self.edgeInsets)];
}

- (CGSize)intrinsicContentSize
{
    CGSize size = [super intrinsicContentSize];
    size.width  += self.edgeInsets.left + self.edgeInsets.right;
    size.height += self.edgeInsets.top + self.edgeInsets.bottom;
    return size;
}

@end

Swift 3 &自动布局兼容版本:

class InsetLabel: UILabel {

    var insets = UIEdgeInsets()

    convenience init(insets: UIEdgeInsets) {
        self.init(frame: CGRect.zero)
        self.insets = insets
    }

    convenience init(dx: CGFloat, dy: CGFloat) {
        let insets = UIEdgeInsets(top: dy, left: dx, bottom: dy, right: dx)
        self.init(insets: insets)
    }

    override func drawText(in rect: CGRect) {
        super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))
    }

    override var intrinsicContentSize: CGSize  {
        var size = super.intrinsicContentSize
        size.width += insets.left + insets.right
        size.height += insets.top + insets.bottom
        return size
    }
}