你需要计算UILabel大小，当你放置嵌入。它可以有不同的行数，因为文本对齐，换行模式。

override func drawText(in rect: CGRect) {

    let size = self.sizeThatFits(UIEdgeInsetsInsetRect(rect, insets).size);
    super.drawText(in: CGRect.init(origin: CGPoint.init(x: insets.left, y: insets.top), size: size));
}

override var intrinsicContentSize: CGSize {

    var size = super.intrinsicContentSize;

    if text == nil || text?.count == 0 {
        return size;
    }

    size = self.sizeThatFits(UIEdgeInsetsInsetRect(CGRect.init(origin: CGPoint.zero, size: size), insets).size);
    size.width  += self.insets.left + self.insets.right;
    size.height += self.insets.top + self.insets.bottom;

    return size;
}

尝试 iEun/InsetLabel

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];

要扩展Brody Robertson提供的答案，您可以添加IB可设计位。这意味着您可以在Storyboard中调整标签。

在你的子类UILabel做

#import <UIKit/UIKit.h>

IB_DESIGNABLE

@interface insetLabel : UILabel

@property (nonatomic, assign) IBInspectable CGFloat leftEdge;
@property (nonatomic, assign) IBInspectable CGFloat rightEdge;
@property (nonatomic, assign) IBInspectable CGFloat topEdge;
@property (nonatomic, assign) IBInspectable CGFloat bottomEdge;

@property (nonatomic, assign) UIEdgeInsets edgeInsets;

@end

然后做;

#import "insetLabel.h"

@implementation insetLabel

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

- (void)drawTextInRect:(CGRect)rect
{
    self.edgeInsets = UIEdgeInsetsMake(self.topEdge, self.leftEdge, self.bottomEdge, self.rightEdge);

    [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

EDIT

你应该为edgeInsets添加一个setter方法。

在Swift中，它是这样解决的。

class Label: UILabel {
    override func drawTextInRect(rect: CGRect) {
        super.drawTextInRect(UIEdgeInsetsInsetRect(rect, UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 10)))
    }
}

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

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。