Swift 4 & 5

改变UIButton图像的方向(RTL和LTR)

extension UIButton {
    func changeDirection(){
       isArabic ? (self.contentHorizontalAlignment = .right) : (self.contentHorizontalAlignment = .left)
        // left-right margin 
        self.imageEdgeInsets = UIEdgeInsets(top: 0, left: 5, bottom: 0, right: 5)
        self.titleEdgeInsets = UIEdgeInsets(top: 0, left: 5, bottom: 0, right: 5)
    }
}

子类化UIButton是完全没有必要的。相反，你可以简单地为图像设置一个高的左插入值，为标题设置一个小的右插入值。就像这样:

button.imageEdgeInsets = UIEdgeInsetsMake(0., button.frame.size.width - (image.size.width + 15.), 0., 0.);
button.titleEdgeInsets = UIEdgeInsetsMake(0., 0., 0., image.size.width);

在Piotr Tomasik的优雅解决方案的基础上:如果你想在按钮标签和图像之间有一点间距，那么包括在你的边缘嵌入如下(复制我的代码在这里完美地为我工作):

    CGFloat spacing          = 3;
    CGFloat insetAmount      = 0.5 * spacing;

    // First set overall size of the button:
    button.contentEdgeInsets = UIEdgeInsetsMake(0, insetAmount, 0, insetAmount);
    [button sizeToFit];

    // Then adjust title and image insets so image is flipped to the right and there is spacing between title and image:
    button.titleEdgeInsets   = UIEdgeInsetsMake(0, -button.imageView.frame.size.width - insetAmount, 0,  button.imageView.frame.size.width  + insetAmount);
    button.imageEdgeInsets   = UIEdgeInsetsMake(0, button.titleLabel.frame.size.width + insetAmount, 0, -button.titleLabel.frame.size.width - insetAmount);

感谢Piotr的解决方案!

Erik

这里是解决方案的UIButton与中心对齐的内容。 这段代码使图像右对齐，并允许使用imageEdgeInsets和titleEdgeInsets进行宝贵的定位。

用你的自定义类子类化UIButton并添加:

- (CGRect)imageRectForContentRect:(CGRect)contentRect {
    CGRect frame = [super imageRectForContentRect:contentRect];
    CGFloat imageWidth = frame.size.width;
    CGRect titleRect = CGRectZero;
    titleRect.size = [[self titleForState:self.state] sizeWithAttributes:@{NSFontAttributeName: self.titleLabel.font}];
    titleRect.origin.x = (self.frame.size.width - (titleRect.size.width + imageWidth)) / 2.0 + self.titleEdgeInsets.left - self.titleEdgeInsets.right;
    frame.origin.x = titleRect.origin.x + titleRect.size.width - self.imageEdgeInsets.right + self.imageEdgeInsets.left;
    return frame;
}

- (CGRect)titleRectForContentRect:(CGRect)contentRect {
    CGFloat imageWidth = [self imageForState:self.state].size.width;
    CGRect frame = [super titleRectForContentRect:contentRect];
    frame.origin.x = (self.frame.size.width - (frame.size.width + imageWidth)) / 2.0 + self.titleEdgeInsets.left - self.titleEdgeInsets.right;
    return frame;
}

最简单的解决方案:

iOS 10及以上版本，Swift:

button.transform = CGAffineTransform(scaleX: -1.0, y: 1.0)
button.titleLabel?.transform = CGAffineTransform(scaleX: -1.0, y: 1.0)
button.imageView?.transform = CGAffineTransform(scaleX: -1.0, y: 1.0)

在iOS 10之前，Swift/Obj-C:

button.transform = CGAffineTransformMakeScale(-1.0, 1.0);
button.titleLabel.transform = CGAffineTransformMakeScale(-1.0, 1.0);
button.imageView.transform = CGAffineTransformMakeScale(-1.0, 1.0);

iOS 9及以上版本，Swift:(推荐)

button.semanticContentAttribute = .forceRightToLeft

如果这需要在UIBarButtonItem中完成，则应该使用额外的视图包装 这是可行的

let view = UIView()
let button = UIButton()
button.setTitle("Skip", for: .normal)
button.setImage(#imageLiteral(resourceName:"forward_button"), for: .normal)
button.semanticContentAttribute = .forceRightToLeft
button.sizeToFit()
view.addSubview(button)
view.frame = button.bounds
navigationItem.rightBarButtonItem = UIBarButtonItem(customView: view)

这行不通

let button = UIButton()
button.setTitle("Skip", for: .normal)
button.setImage(#imageLiteral(resourceName:"forward_button"), for: .normal)
button.semanticContentAttribute = .forceRightToLeft
button.sizeToFit()
navigationItem.rightBarButtonItem = UIBarButtonItem(customView: button)