How to remove the top and bottom padding of UIButton, when create it using auto layout?

Question

When create UIButton with auto layout, the intrinsicContentSize always contain different top/bottom padding according to different text font size. I try to set contentEdgeInsets, but it not really works for top/bottom padding.

How to fix the padding to 0 or any constant value?

Answer 1

After some experimentation, it appears that if you try and set contentEdgeInsets to all zeros, the default insets are used. However, if you set them to nearly zero, it works:

button.contentEdgeInsets = UIEdgeInsets(top: 0, left: 0.01, bottom: 0.01, right: 0)

It also appears that the values get floor'd, so you won't actually get fractional padding.

Answer 2

Updated for Swift 5

If you are wanting the button to size to its titleLabel's contents, I found that the only way to do so is by subclassing UIButton and overriding intrinsicContentSize. Hope this works for you!

class CustomButton: UIButton {
    override var intrinsicContentSize: CGSize {
        return titleLabel?.intrinsicContentSize ?? super.intrinsicContentSize
    }
}

If you need to use titleEdgeInsets, you can update your UIButton subclass like this:

class CustomButton: UIButton {
    override var titleEdgeInsets: UIEdgeInsets {
        didSet {
            invalidateIntrinsicContentSize()
        }
    }

    override var intrinsicContentSize: CGSize {
        var sizeWithInsets = titleLabel?.intrinsicContentSize ?? super.intrinsicContentSize
        sizeWithInsets.width += titleEdgeInsets.left + titleEdgeInsets.right
        sizeWithInsets.height += titleEdgeInsets.top + titleEdgeInsets.bottom
        return sizeWithInsets
    }
}