Swift 3基于pegpeg的答案:

extension UIButton {

    override open var intrinsicContentSize: CGSize {

        let intrinsicContentSize = super.intrinsicContentSize

        let adjustedWidth = intrinsicContentSize.width + titleEdgeInsets.left + titleEdgeInsets.right
        let adjustedHeight = intrinsicContentSize.height + titleEdgeInsets.top + titleEdgeInsets.bottom

        return CGSize(width: adjustedWidth, height: adjustedHeight)

    }

}

斯威夫特是这样做的:

extension UIButton {
    override open var intrinsicContentSize: CGSize {
        let intrinsicContentSize = super.intrinsicContentSize

        let adjustedWidth = intrinsicContentSize.width + titleEdgeInsets.left + titleEdgeInsets.right
        let adjustedHeight = intrinsicContentSize.height + titleEdgeInsets.top + titleEdgeInsets.bottom

        return CGSize(width: adjustedWidth, height: adjustedHeight)
    }
}

爱你斯威夫特

Swift 3基于pegpeg的答案:

extension UIButton {

    override open var intrinsicContentSize: CGSize {

        let intrinsicContentSize = super.intrinsicContentSize

        let adjustedWidth = intrinsicContentSize.width + titleEdgeInsets.left + titleEdgeInsets.right
        let adjustedHeight = intrinsicContentSize.height + titleEdgeInsets.top + titleEdgeInsets.bottom

        return CGSize(width: adjustedWidth, height: adjustedHeight)

    }

}

为什么不重写UIView上的intrinsicContentSize方法?例如:

- (CGSize) intrinsicContentSize
{
    CGSize s = [super intrinsicContentSize];

    return CGSizeMake(s.width + self.titleEdgeInsets.left + self.titleEdgeInsets.right,
                      s.height + self.titleEdgeInsets.top + self.titleEdgeInsets.bottom);
}

这应该告诉自动布局系统，它应该增加按钮的大小，以允许插入和显示全文。我不在我自己的电脑前，所以我还没有测试这个。

我使用的解决方案是在按钮上添加宽度限制。然后在初始化的某个地方，在你的文本设置好之后，像这样更新宽度约束:

self.buttonWidthConstraint.constant = self.shareButton.intrinsicContentSize.width + 8;

8是你的插入数。

该选项在接口构建器中也可用。请看插图。我将左右各设为3。效果非常好。