我有以下代码…
UILabel *buttonLabel = [[UILabel alloc] initWithFrame:targetButton.bounds];
buttonLabel.text = @"Long text string";
[targetButton addSubview:buttonLabel];
[targetButton bringSubviewToFront:buttonLabel];
.．.这个想法是，我可以有多行文本的按钮，但文本总是被UIButton的backgroundImage掩盖。显示按钮子视图的日志调用显示UILabel已添加，但文本本身无法看到。这是UIButton的bug还是我做错了什么?
当前回答
斯威夫特4.0
btn.titleLabel?.lineBreakMode = .byWordWrapping
btn.titleLabel?.textAlignment = .center
btn.setTitle( "Line1\nLine2", for: .normal)
其他回答
如果你在iOS 6上使用自动布局，你可能还需要设置preferredmaxlayoutidth属性:
button.titleLabel.lineBreakMode = NSLineBreakByWordWrapping;
button.titleLabel.textAlignment = NSTextAlignmentCenter;
button.titleLabel.preferredMaxLayoutWidth = button.frame.size.width;
这里的答案告诉你如何实现多行按钮标题编程。
我只是想添加，如果你正在使用故事板，你可以输入[Ctrl+Enter]强制在按钮标题字段换行。
HTH
基于@Amir Khorsandi的回答-但如果你有一个带有图像的按钮:
extension UIButton {
func enableMultiline() {
setContentHuggingPriority(.defaultLow, for: .vertical) // high hugging priority could squeeze the button to 1 line
titleLabel?.numberOfLines = 0
titleLabel?.setContentCompressionResistancePriority(.required, for: .vertical)
titleLabel?.topAnchor.constraint(greaterThanOrEqualTo: topAnchor).isActive = true
titleLabel?.bottomAnchor.constraint(lessThanOrEqualTo: bottomAnchor).isActive = true
imageView?.setContentCompressionResistancePriority(.required, for: .horizontal) // otherwise image could be squeezed
}
}
滚动您自己的按钮类。从长远来看，这是目前为止最好的解决方案。UIButton和其他UIKit类在如何自定义它们方面是非常受限的。
我有一个自动布局的问题，启用多行后的结果是这样的: 所以titleLabel大小不影响按钮大小 我添加了基于contenttedgeinsets的约束(在这种情况下，contenttedgeinsets是(10,10,10,10) 调用makeMultiLineSupport()后: 希望它能帮助你(swift 5.0):
extension UIButton {
func makeMultiLineSupport() {
guard let titleLabel = titleLabel else {
return
}
titleLabel.numberOfLines = 0
titleLabel.setContentHuggingPriority(.required, for: .vertical)
titleLabel.setContentHuggingPriority(.required, for: .horizontal)
addConstraints([
.init(item: titleLabel,
attribute: .top,
relatedBy: .greaterThanOrEqual,
toItem: self,
attribute: .top,
multiplier: 1.0,
constant: contentEdgeInsets.top),
.init(item: titleLabel,
attribute: .bottom,
relatedBy: .greaterThanOrEqual,
toItem: self,
attribute: .bottom,
multiplier: 1.0,
constant: contentEdgeInsets.bottom),
.init(item: titleLabel,
attribute: .left,
relatedBy: .greaterThanOrEqual,
toItem: self,
attribute: .left,
multiplier: 1.0,
constant: contentEdgeInsets.left),
.init(item: titleLabel,
attribute: .right,
relatedBy: .greaterThanOrEqual,
toItem: self,
attribute: .right,
multiplier: 1.0,
constant: contentEdgeInsets.right)
])
}
}
