可以使用https://github.com/mattt/TTTAttributedLabel代替UILabel

BITAttributedLabel *label = [BITAttributedLabel new];
label.font = font;
label.text = @"hello";
label.textInsets = UIEdgeInsetsMake(10, 10, 10, 10);
[label sizeToFit];

#import "E_LabelWithPadding.h"
#define padding UIEdgeInsetsMake(2, 0, 2, 0)
#define padding1 UIEdgeInsetsMake(0, 0, 0, 0)
@implementation E_LabelWithPadding
- (void)drawTextInRect:(CGRect)rect {
if (![self.text isEqualToString:@""]) {
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, padding)];
}else {
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, padding1)];
}

}

- (CGSize) intrinsicContentSize {
if (![self.text isEqualToString:@""]) {
    CGSize superContentSize = [super intrinsicContentSize];
    CGFloat width = superContentSize.width + padding.left + padding.right;
    CGFloat height = superContentSize.height + padding.top + padding.bottom;
    return CGSizeMake(width, height);
}else {
    CGSize superContentSize = [super intrinsicContentSize];
    CGFloat width = superContentSize.width + padding1.left + padding1.right;
    CGFloat height = superContentSize.height + padding1.top + padding1.bottom;
    return CGSizeMake(width, height);
}

}

- (CGSize) sizeThatFits:(CGSize)size {
if (![self.text isEqualToString:@""]) {
    CGSize superSizeThatFits = [super sizeThatFits:size];
    CGFloat width = superSizeThatFits.width + padding.left + padding.right;
    CGFloat height = superSizeThatFits.height + padding.top + padding.bottom;
    return CGSizeMake(width, height);
}else {
    CGSize superSizeThatFits = [super sizeThatFits:size];
    CGFloat width = superSizeThatFits.width + padding1.left + padding1.right;
    CGFloat height = superSizeThatFits.height + padding1.top + padding1.bottom;
    return CGSizeMake(width, height);
}

}

@end

对于这样一个简单的情况，子类化有点麻烦。另一种方法是将没有背景设置的UILabel添加到有背景设置的UIView中。将标签的x设置为10，并使外部视图的大小比标签宽20个像素。

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)))
    }
}

设置标签的textAlignment属性为NSTextAlignmentRight并增加它的宽度。

很多答案都缺少对sizeThatFits的重写。有了这个子类，你可以创建标签，设置填充，然后输入label。sizetofit()，瞧。

import UIKit

class UILabelEx : UILabel
{
    var padding : UIEdgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)

    override func drawTextInRect(rect: CGRect) {

        super.drawTextInRect(UIEdgeInsetsInsetRect(rect, padding))
    }

    override func sizeThatFits(size: CGSize) -> CGSize
    {

        var adjSize = super.sizeThatFits(size)
        adjSize.width += padding.left + padding.right
        adjSize.height += padding.top + padding.bottom

        return adjSize
    }
}