关于实现UIButton的上图下文、上文下图、左图右文、右图左文的布局需求，我也尝试过扩展分类使用EdgeInsets来实现，但总是不太灵活不太如意。
于是我选择了暴力解决办法：使用UIButton的子类，重写layoutSubviews。

JXLayoutButton

JXLayoutButton.h

//
//  JXLayoutButton.h
//  JXLayoutButtonDemo
//
//  Created by JiongXing on 16/9/24.
//  Copyright © 2016年 JiongXing. All rights reserved.
//

#import <UIKit/UIKit.h>

typedef NS_ENUM(NSUInteger, JXLayoutButtonStyle) {
    JXLayoutButtonStyleLeftImageRightTitle,
    JXLayoutButtonStyleLeftTitleRightImage,
    JXLayoutButtonStyleUpImageDownTitle,
    JXLayoutButtonStyleUpTitleDownImage
};

/// 重写layoutSubviews的方式实现布局，忽略imageEdgeInsets、titleEdgeInsets和contentEdgeInsets
@interface JXLayoutButton : UIButton

/// 布局方式
@property (nonatomic, assign) JXLayoutButtonStyle layoutStyle;
/// 图片和文字的间距，默认值8
@property (nonatomic, assign) CGFloat midSpacing;
/// 指定图片size
@property (nonatomic, assign) CGSize imageSize;

@end

JXLayoutButton.m

//
//  JXLayoutButton.m
//  JXLayoutButtonDemo
//
//  Created by JiongXing on 16/9/24.
//  Copyright © 2016年 JiongXing. All rights reserved.
//

#import "JXLayoutButton.h"

@implementation JXLayoutButton

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        self.midSpacing = 8;
    }
    return self;
}

- (void)layoutSubviews {
    [super layoutSubviews];
    
    if (CGSizeEqualToSize(CGSizeZero, self.imageSize)) {
        [self.imageView sizeToFit];
    }
    else {
        self.imageView.frame = CGRectMake(self.imageView.frame.origin.x,
                                          self.imageView.frame.origin.y,
                                          self.imageSize.width,
                                          self.imageSize.height);
    }
    [self.titleLabel sizeToFit];
    
    switch (self.layoutStyle) {
        case JXLayoutButtonStyleLeftImageRightTitle:
            [self layoutHorizontalWithLeftView:self.imageView rightView:self.titleLabel];
            break;
        case JXLayoutButtonStyleLeftTitleRightImage:
            [self layoutHorizontalWithLeftView:self.titleLabel rightView:self.imageView];
            break;
        case JXLayoutButtonStyleUpImageDownTitle:
            [self layoutVerticalWithUpView:self.imageView downView:self.titleLabel];
            break;
        case JXLayoutButtonStyleUpTitleDownImage:
            [self layoutVerticalWithUpView:self.titleLabel downView:self.imageView];
            break;
        default:
            break;
    }
}

- (void)layoutHorizontalWithLeftView:(UIView *)leftView rightView:(UIView *)rightView {
    CGRect leftViewFrame = leftView.frame;
    CGRect rightViewFrame = rightView.frame;
    
    CGFloat totalWidth = CGRectGetWidth(leftViewFrame) + self.midSpacing + CGRectGetWidth(rightViewFrame);
    
    leftViewFrame.origin.x = (CGRectGetWidth(self.frame) - totalWidth) / 2.0;
    leftViewFrame.origin.y = (CGRectGetHeight(self.frame) - CGRectGetHeight(leftViewFrame)) / 2.0;
    leftView.frame = leftViewFrame;
    
    rightViewFrame.origin.x = CGRectGetMaxX(leftViewFrame) + self.midSpacing;
    rightViewFrame.origin.y = (CGRectGetHeight(self.frame) - CGRectGetHeight(rightViewFrame)) / 2.0;
    rightView.frame = rightViewFrame;
}

- (void)layoutVerticalWithUpView:(UIView *)upView downView:(UIView *)downView {
    CGRect upViewFrame = upView.frame;
    CGRect downViewFrame = downView.frame;
    
    CGFloat totalHeight = CGRectGetHeight(upViewFrame) + self.midSpacing + CGRectGetHeight(downViewFrame);
    
    upViewFrame.origin.y = (CGRectGetHeight(self.frame) - totalHeight) / 2.0;
    upViewFrame.origin.x = (CGRectGetWidth(self.frame) - CGRectGetWidth(upViewFrame)) / 2.0;
    upView.frame = upViewFrame;
    
    downViewFrame.origin.y = CGRectGetMaxY(upViewFrame) + self.midSpacing;
    downViewFrame.origin.x = (CGRectGetWidth(self.frame) - CGRectGetWidth(downViewFrame)) / 2.0;
    downView.frame = downViewFrame;
}

- (void)setImage:(UIImage *)image forState:(UIControlState)state {
    [super setImage:image forState:state];
    [self setNeedsLayout];
}

- (void)setTitle:(NSString *)title forState:(UIControlState)state {
    [super setTitle:title forState:state];
    [self setNeedsLayout];
}

- (void)setMidSpacing:(CGFloat)midSpacing {
    _midSpacing = midSpacing;
    [self setNeedsLayout];
}

- (void)setImageSize:(CGSize)imageSize {
    _imageSize = imageSize;
    [self setNeedsLayout];
}

@end

测试

//
//  ViewController.m
//  JXLayoutButtonDemo
//
//  Created by JiongXing on 16/9/24.
//  Copyright © 2016年 JiongXing. All rights reserved.
//

#import "ViewController.h"
#import "JXLayoutButton.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    CGFloat margin = 20;
    CGFloat buttonWidth = (CGRectGetWidth(self.view.frame) - 20 * 3) / 2.0;
    CGFloat buttonHeight = buttonWidth;
    
    [self addButton: [self generateButtonWithStyle:JXLayoutButtonStyleUpImageDownTitle]
           withFrame:CGRectMake(margin, 64 + margin, buttonWidth, buttonHeight)];
    
    [self addButton: [self generateButtonWithStyle:JXLayoutButtonStyleUpTitleDownImage]
          withFrame:CGRectMake(margin + buttonWidth + margin, 64 + margin, buttonWidth, buttonHeight)];
    
    [self addButton: [self generateButtonWithStyle:JXLayoutButtonStyleLeftImageRightTitle]
          withFrame:CGRectMake(margin, 64 + margin + buttonHeight + margin, buttonWidth, buttonHeight)];
    
    [self addButton: [self generateButtonWithStyle:JXLayoutButtonStyleLeftTitleRightImage]
          withFrame:CGRectMake(margin + buttonWidth + margin, 64 + margin + buttonHeight + margin, buttonWidth, buttonHeight)];
    
    JXLayoutButton *customSizeButton = [self generateButtonWithStyle:JXLayoutButtonStyleUpImageDownTitle];
    [customSizeButton setTitle:@"SmallSize" forState:UIControlStateNormal];
    customSizeButton.imageSize = CGSizeMake(100 / 4, 140 / 4);
    [self addButton:customSizeButton
          withFrame:CGRectMake((CGRectGetWidth(self.view.frame) - buttonWidth) / 2.0, 64 + margin * 3 + buttonHeight * 2, buttonWidth, buttonHeight)];
}

- (JXLayoutButton *)generateButtonWithStyle:(JXLayoutButtonStyle)style {
    JXLayoutButton *button = [JXLayoutButton buttonWithType:UIButtonTypeCustom];
    [button setImage:[UIImage imageNamed:@"luffy"] forState:UIControlStateNormal];
    [button setTitle:@"Luffy" forState:UIControlStateNormal];
    [button setTitleColor:[UIColor darkTextColor] forState:UIControlStateNormal];
    button.layoutStyle = style;
    
    button.layer.borderWidth = 1;
    button.layer.borderColor = [UIColor magentaColor].CGColor;
    return button;
}

- (void)addButton:(JXLayoutButton *)button withFrame:(CGRect)frame {
    button.frame = frame;
    [self.view addSubview:button];
}
@end

结果如上图。
项目源码：https://github.com/JiongXing/JXLayoutButton
下载地址：https://github.com/JiongXing/JXLayoutButton/archive/master.zip