在UILabel上使用捏手势调整字体和标签框架的大小? [英] Resize font along with frame of label using pinch gesture on UILabel?
本文介绍了在UILabel上使用捏手势调整字体和标签框架的大小?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
每当用户使用捏手势调整标签大小时,即可平滑地增大或减小字体大小.
Increase or decrease font size smoothly whenever user resize label using pinch gesture on it.
注意
- 在不影响字体质量的情况下
- 不仅改变了UILabel的规模
- 支持多行文字
- 旋转手势应与捏手势配合使用
- 参考:SnapChat或Instagram文本编辑器工具
extension String {
func height(withConstrainedWidth width: CGFloat, font: UIFont) -> CGFloat {
let constraintRect = CGSize(width: width, height: .greatestFiniteMagnitude)
let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSAttributedStringKey.font: UIFont(name: font.fontName, size: font.pointSize)!], context: nil)
return ceil(boundingBox.height)
}
func width(withConstrainedHeight height: CGFloat, font: UIFont) -> CGFloat {
let constraintRect = CGSize(width: .greatestFiniteMagnitude, height: height)
let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSAttributedStringKey.font: UIFont(name: font.fontName, size: font.pointSize)!], context: nil)
return ceil(boundingBox.width)
}
}
func resizeLabelToText(textLabel : UILabel)
{
let labelFont = textLabel.font
let labelString = textLabel.text
let labelWidth : CGFloat = labelString!.width(withConstrainedHeight: textLabel.frame.size.height, font: labelFont!)
let labelHeight : CGFloat = labelString!.height(withConstrainedWidth: labelWidth, font: labelFont!)
textLabel.frame = CGRect(x: textLabel.frame.origin.x, y: textLabel.frame.origin.y, width: labelWidth, height: labelHeight)
textLabel.font = labelFont
}
func pinchedRecognize(_ pinchGesture: UIPinchGestureRecognizer) {
guard pinchGesture.view != nil else {return}
if (pinchGesture.view is UILabel) {
let selectedTextLabel = pinchGesture.view as! UILabel
if pinchGesture.state == .began || pinchGesture.state == .changed {
let pinchScale = round(pinchGesture.scale * 1000) / 1000.0
if (pinchScale < 1) {
selectedTextLabel.font = selectedTextLabel.font.withSize(selectedTextLabel.font.pointSize - pinchScale)
}
else {
selectedTextLabel.font = selectedTextLabel.font.withSize(selectedTextLabel.font.pointSize + pinchScale)
}
resizeLabelToText(textLabel: selectedTextLabel)
}
}
}
推荐答案
我用以下代码解决了该问题,该代码可以很好地处理所提及的各个方面,类似于Snapchat和Instagram:
var pointSize: CGFloat = 0
@objc func pinchRecoginze(_ pinchGesture: UIPinchGestureRecognizer) {
guard pinchGesture.view != nil else {return}
let view = pinchGesture.view!
if (pinchGesture.view is UILabel) {
let textLabel = view as! UILabel
if pinchGesture.state == .began {
let font = textLabel.font
pointSize = font!.pointSize
pinchGesture.scale = textLabel.font!.pointSize * 0.1
}
if 1 <= pinchGesture.scale && pinchGesture.scale <= 10 {
textLabel.font = UIFont(name: textLabel.font!.fontName, size: pinchGesture.scale * 10)
resizeLabelToText(textLabel: textLabel)
}
}
}
func resizeLabelToText(textLabel : UILabel) {
let labelSize = textLabel.intrinsicContentSize
textLabel.bounds.size = labelSize
}
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