以下提供了一般性方案,可使图像在文本上方水平居中显示,而不需要使用任何神奇数字。 不过请注意,下面的代码已经过时了,你应该使用下面更新版本之一:
CGFloat spacing = 6.0;
CGSize imageSize = button.imageView.frame.size;
button.titleEdgeInsets = UIEdgeInsetsMake(
0.0, - imageSize.width, - (imageSize.height + spacing), 0.0);
CGSize titleSize = button.titleLabel.frame.size;
button.imageEdgeInsets = UIEdgeInsetsMake(
- (titleSize.height + spacing), 0.0, 0.0, - titleSize.width);
以下版本包含为支持iOS 7+所做的更改,这些更改在下面的评论中被推荐。我自己没有测试过此代码,因此不确定它的工作效果如何,或者是否会在早期版本的iOS下使用时出现问题。
CGFloat spacing = 6.0;
CGSize imageSize = button.imageView.image.size;
button.titleEdgeInsets = UIEdgeInsetsMake(
0.0, - imageSize.width, - (imageSize.height + spacing), 0.0);
CGSize titleSize = [button.titleLabel.text sizeWithAttributes:@{NSFontAttributeName: button.titleLabel.font}];
button.imageEdgeInsets = UIEdgeInsetsMake(
- (titleSize.height + spacing), 0.0, 0.0, - titleSize.width);
CGFloat edgeOffset = fabsf(titleSize.height - imageSize.height) / 2.0;
button.contentEdgeInsets = UIEdgeInsetsMake(edgeOffset, 0.0, edgeOffset, 0.0);
Swift 5.0 版本
extension UIButton {
func alignVertical(spacing: CGFloat = 6.0) {
guard let imageSize = imageView?.image?.size,
let text = titleLabel?.text,
let font = titleLabel?.font
else { return }
titleEdgeInsets = UIEdgeInsets(
top: 0.0,
left: -imageSize.width,
bottom: -(imageSize.height + spacing),
right: 0.0
)
let titleSize = text.size(withAttributes: [.font: font])
imageEdgeInsets = UIEdgeInsets(
top: -(titleSize.height + spacing),
left: 0.0,
bottom: 0.0,
right: -titleSize.width
)
let edgeOffset = abs(titleSize.height - imageSize.height) / 2.0
contentEdgeInsets = UIEdgeInsets(
top: edgeOffset,
left: 0.0,
bottom: edgeOffset,
right: 0.0
)
}
}
button.currentTitle
比button.titleLabel.text
更好,特别是当按钮文本将来可能会更改时。currentTitle
会立即填充,而titleLabel.text
变化缓慢,这可能导致不对齐的插图。 - mjangda