编辑:这个真的很老了。上面有更好的解决方案。

我最终只是在文本中添加了一些空格:

self.titleLabel.text = [NSString stringWithFormat:@"    %@", self.titleLabel.text];

丑陋但有效，不需要子类化。

你也可以试试“\t”。对于一般的解决方案，请参考已接受的答案

我认为UILabel类没有设置边距的方法。为什么不把标签的位置设置在需要的位置?

见下面的代码:

UILabel *label = [[UILabel alloc] init];
label.text = @"This is label";
label.frame = CGRectMake(0,0,100,100);

如果来自接口构建器，则按以下方式定位Label:

yourLabel.frame = CGRectMake(0,0,100,100);

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

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)))
    }
}

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。

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)];