UILabel

• 建立可以調整Label內，字跟Label之間間距的Label

import UIKit

class InsetLabel:UILabel {

    var textInsets = UIEdgeInsets.zero {
        didSet { invalidateIntrinsicContentSize() }
    }

    override func textRect(forBounds bounds: CGRect, limitedToNumberOfLines numberOfLines: Int) -> CGRect {
        let insetRect = UIEdgeInsetsInsetRect(bounds, textInsets)
        let textRect = super.textRect(forBounds: insetRect, limitedToNumberOfLines: numberOfLines)
        let invertedInsets = UIEdgeInsets(top: -textInsets.top, left: -textInsets.left, bottom: -textInsets.bottom, right: -textInsets.right)
        return UIEdgeInsetsInsetRect(textRect, invertedInsets)
    }

    override func drawText(in rect: CGRect) {
        super.drawText(in: UIEdgeInsetsInsetRect(rect, textInsets))
    }
}

// 這是用來讓IB提供可設定的圖形化介面
@IBDesignable
extension InsetLabel {

    @IBInspectable
    var leftTextInset: CGFloat {
        set { textInsets.left = newValue }
        get { return textInsets.left }
    }
    @IBInspectable
    var rightTextInset: CGFloat {
        set { textInsets.right = newValue }
        get { return textInsets.right }
    }
    @IBInspectable
    var topTextInset: CGFloat {
        set { textInsets.top = newValue }
        get { return textInsets.top }
    }
    @IBInspectable
    var bottomTextInset: CGFloat {
        set { textInsets.bottom = newValue }
        get { return textInsets.bottom }
    }
}