自适应titleLabel大小的UIButton

Question

自适应titleLabel大小的UIButton

42

我有一个UIButton，我将其添加到故事板中的视图控制器的视图中。我添加居中约束来定位它，并添加前导空间约束来限制其宽度。在代码中，我添加：

self.button.titleLabel.numberOfLines = 0;
self.button.titleLabel.lineBreakMode = NSLineBreakByWordWrapping;
[self.button setTitle:@"A real real real real real real real real long long name." forState:UIControlStateNormal];
self.button.backgroundColor = [UIColor redColor];
self.button.titleLabel.backgroundColor = [UIColor blueColor];

下面显示结果：

我希望按钮根据其内容大小调整大小。我该如何做？

我已经尝试过

[self.button sizeToFit];

我已经尝试将内容抱紧和压缩阻力自动布局约束的优先级设置为必需。

我还尝试了显式地设置 contentEdgeInsets 和 titleEdgeInsets 为 UIEdgeInsetsZero 并调用 invalidateIntrinsicContentSize。

我还注意到，如果在标题字符串中放置换行符，则按钮似乎会调整大小以适应其内容。

我正在 iPhone 6 模拟器上运行 Xcode 6 和 iOS 8。

- Darren

13个回答

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- ToxicAbe · Answer 1

/*
In SWIFT : Create an IBDesignable sub class of UIButton and override the intrinsicContentSize as shown below. It will resize appropriately for text and images. Then change your line break property to Word Wrap. Add a "fixedWidth" inspectable property that will adjust the height if you need buttons with fixed widths or when set to false will adjust the width and keep the height fixed.
*/

import UIKit

@IBDesignable
class UIButtonX: UIButton {
    
    //...

    @IBInspectable var fixedWidth : Bool = true
override var intrinsicContentSize: CGSize {
    let labelSize = titleLabel?.sizeThatFits(CGSize(width: fixedWidth ? frame.width : .greatestFiniteMagnitude, height: fixedWidth ? .greatestFiniteMagnitude : frame.height)) ?? .zero

    let wImage = image(for: [])?.size.width ?? 0
    let wTitleInset = titleEdgeInsets.left + titleEdgeInsets.right
    let wImageInset = imageEdgeInsets.left + imageEdgeInsets.right
    let wContentInset = contentEdgeInsets.left + contentEdgeInsets.right
    let width : CGFloat = labelSize.width + wImage + wTitleInset + wImageInset + wContentInset
    
    let biggerHeight = max(image(for: [])?.size.height ?? 0, labelSize.height)
    let hTitleInset = titleEdgeInsets.top + titleEdgeInsets.bottom
    let hImageInset = imageEdgeInsets.top + imageEdgeInsets.bottom
    let hContentInset = contentEdgeInsets.top + contentEdgeInsets.bottom
    let height : CGFloat = biggerHeight + hTitleInset + hImageInset + hContentInset
    
    let desiredButtonSize = CGSize(width: width, height: height)
    
    return desiredButtonSize
}
    
    //...

}

- looseyi · Answer 2

class SFResizableButton: UIButton {
  override var intrinsicContentSize: CGSize {
    get {
      var labelSize = CGSize.zero
        if let text = titleLabel?.text, let font = titleLabel?.font {
          labelSize.width = text.width(constrained: .greatestFiniteMagnitude, font: font)
        } else if let att = titleLabel?.attributedText {
          labelSize.width = att.width(constrained: .greatestFiniteMagnitude)
        }
      if let imageView = imageView {
        labelSize.width = labelSize.width + imageView.frame.width
      }
      let desiredButtonSize = CGSize(width: ceil(labelSize.width) + titleEdgeInsets.left + titleEdgeInsets.right + imageEdgeInsets.left + imageEdgeInsets.right, height: labelSize.height + titleEdgeInsets.top + titleEdgeInsets.bottom + imageEdgeInsets.top + imageEdgeInsets.bottom)

        return desiredButtonSize
    }
  }
}
extesion String {
  func width(constrained height: CGFloat, font: UIFont) -> CGFloat {
    let constraintRect = CGSize(width: .greatestFiniteMagnitude, height: height)
      let boundingBox = (self as NSString).boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)

      return boundingBox.width
  }
}

extension NSAttributedString {
  func width(constrained height: CGFloat) -> CGFloat {
    let constraintRect = CGSize(width: .greatestFiniteMagnitude, height: height)
      let boundingBox = boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, context: nil)

      return boundingBox.width
  }
}

- zeiteisen · Answer 3

我创建了一个子类，它在UITableViewCell内部运行良好。如果您想要像截图中那样在按钮周围添加边框，这是必需的。

import Foundation
import UIKit

class IntrinsicTitleButton: UIButton {
    
    override var intrinsicContentSize: CGSize {
       let labelSize = titleLabel?.sizeThatFits(CGSize(width: frame.width - titleEdgeInsets.left - titleEdgeInsets.right, height: .greatestFiniteMagnitude)) ?? .zero
       let desiredButtonSize = CGSize(width: labelSize.width + titleEdgeInsets.left + titleEdgeInsets.right, height: labelSize.height + titleEdgeInsets.top + titleEdgeInsets.bottom)

       return desiredButtonSize
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
    }
    
    override init(frame: CGRect) {
        super.init(frame: frame)
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        invalidateIntrinsicContentSize()
    }
    
    func setup() {
        titleLabel?.lineBreakMode = .byWordWrapping
    }
    
    override func setTitle(_ title: String?, for state: UIControl.State) {
        super.setTitle(title, for: state)
        layoutIfNeeded()
    }
    
}