如果你在ios6 +中使用自动布局，你可以通过在UILabel的子类中调整intrinsicContentSize来实现。

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        self.textAlignment = NSTextAlignmentRight;
    }
    return self;
}

- (CGSize)intrinsicContentSize 
{
    CGSize size = [super intrinsicContentSize];
    return CGSizeMake(size.width + 10.0, size.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

为了消除单行标签的垂直填充，我做了:

// I have a category method setFrameHeight; you'll likely need to modify the frame.
[label setFrameHeight:font.pointSize];

或者，不带类别，使用:

CGRect frame = label.frame;
frame.size.height = font.pointSize;
label.frame = frame;

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)];

#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。