Swift 中 UIButton 的自定义段落行距

Question

我以编程方式创建了一个简单的大型UIButton ，它显示五行文本，下面是我的 Swift 5 代码。

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问题

使用代码，如何更改UIButton的属性以增加或减少每行文本之间的行距？ 例如，如何创建双倍行距或创建半行距？

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代码

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        
        super.viewDidLoad()
        
        addMyButton()
        
    }
    
    func addMyButton() {
        
        let myButtonTitleLabelString = "First\nSecond\nThird\nFourth\nFifth"
        let myButtonTitleFontName = "HelveticaNeue"
        let myButtonTitleFontSize = CGFloat(20)
        let myButton = UIButton(type: UIButton.ButtonType.custom)
        
        myButton.setTitle(myButtonTitleLabelString, for:UIControl.State())
        myButton.titleLabel!.textAlignment = .center
        myButton.titleLabel!.lineBreakMode = .byWordWrapping
        myButton.titleLabel!.font = UIFont(name: myButtonTitleFontName, size: myButtonTitleFontSize)
        myButton.titleEdgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
        myButton.setTitleColor(UIColor.white, for: UIControl.State())
        myButton.backgroundColor = UIColor.orange
        myButton.frame = CGRect(x: 40, y: 100, width: 300, height: 300)
        
        view.addSubview(myButton)
        
    }
     }

Answer 1

代码

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        
        super.viewDidLoad()
        
        addMyButton()
        
    }
    
    func addMyButton() {
        
        let myButtonTitleLabelString = "First\nSecond\nThird\nFourth\nFifth"
        let myButtonTitleFontName = "HelveticaNeue"
        let myButtonTitleFontSize = CGFloat(20)
        let myButton = UIButton(type: UIButton.ButtonType.custom)

//// Note: Remove these next 2 lines
        
//        myButton.setTitle(myButtonTitleLabelString, for:UIControl.State())
//        myButton.titleLabel!.textAlignment = .center

        myButton.titleLabel!.lineBreakMode = .byWordWrapping
        myButton.titleLabel!.font = UIFont(name: myButtonTitleFontName, size: myButtonTitleFontSize)
        myButton.titleEdgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
        myButton.setTitleColor(UIColor.white, for: UIControl.State())
        myButton.backgroundColor = UIColor.orange
        myButton.frame = CGRect(x: 40, y: 100, width: 300, height: 300)
        

//// Note: Add these next 7 lines

//// Note: Change `myButtonParagraphStyleParagraphSpacing` `CGFloat` value to change line spacing; 
////       1 = single line spacing, 2 = double line spacing, 0.5 = half line spacing.

        let myButtonParagraphStyle = NSMutableParagraphStyle()
        let myButtonParagraphStyleParagraphSpacing = CGFloat(2)

        myButtonParagraphStyle.alignment = .center
        myButtonParagraphStyle.paragraphSpacing = (myButtonTitleFontSize * (myButtonParagraphStyleParagraphSpacing - 1))

        let myButtonAttributes = [NSAttributedString.Key.paragraphStyle: myButtonParagraphStyle]
        let myButtonAttributedText = NSAttributedString(string: myButtonTitleLabelString, attributes: myButtonAttributes)

        myButton.setAttributedTitle(myButtonAttributedText, for: UIControl.State())
        

        view.addSubview(myButton)
        
    }
    
}

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