如何在界面生成器 (Xcode 9) 中工作的 UIButton 子类中设置默认标题

Question

I have a button that repeats throughout my app, so I created a subclass to avoid having to set all the basic properties every time.

I am able to set the background colour, the text colour, round the corners.

However, things fall apart when I try to set a default title - something other than "Button". In Interface Builder it ignores the title, but it also then ignores the font colour, which works when I don't set the title.

If I run the app, it all looks fine, but one major point of using Interface Builder is to save the step of constantly running the app to check basic UI layout.

Here is the subclass. Note that if you comment out the 2 setTitle lines, the button shows the correct text colour (white).

import UIKit

@IBDesignable class ContinueButton: UIButton {

    @IBInspectable var titleColour: UIColor = .white {
        didSet {
            setTitleColor(titleColour, for: .normal)
        }
    }

    @IBInspectable var bgColour: UIColor = UIColor.gray {
        didSet {
            backgroundColor = bgColour
        }
    }

    @IBInspectable var buttonTitle: String = "Continue" {
        didSet {
            setTitle(buttonTitle, for: .normal)
        }
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        setAttributes()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setAttributes()
    }

    public func setAttributes() {
        setTitleColor(titleColour, for: .normal)
        backgroundColor = bgColour
        setTitle(buttonTitle, for: .normal)
    }

    override public func layoutSubviews() {
        super.layoutSubviews()

        setAttributes()

        layer.cornerRadius = 0.5 * bounds.size.height
        clipsToBounds = true
    }
}

ps, My main objective is to create a reusable custom button that takes care of setting a bunch of defaults. If there's a better way to achieve that, I'd be very happy to hear that - especially if it could be done visually rather than through code.

Thanks for any advice you can give,

-Nico

Answer 1

Just override prepareForInterfaceBuilder() and add setAttributes().

override func prepareForInterfaceBuilder() {
    super.prepareForInterfaceBuilder()
    setAttributes()
}

Answer 2

The tintColor property will do the trick. button.tintColor = UIColor.red

but to make sure to override the prepareForInterfaceBuilder()

override func prepareForInterfaceBuilder() {
    super.prepareForInterfaceBuilder()
    button.tintColor = UIColor.red
}