我们能否像 UITextField 一样为 UILabel 启用剪切复制粘贴菜单？
如果没有，我需要将我的UILabel 转换为UITextField，如何启用剪切复制粘贴菜单并且不允许修改内容？
【问题讨论】：
标签： ios swift iphone xcode cocoa-touch
对于 Swift 你必须实现这个类：
import UIKit
class CopyableLabel: UILabel {
override init(frame: CGRect) {
super.init(frame: frame)
self.sharedInit()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
self.sharedInit()
}
func sharedInit() {
self.isUserInteractionEnabled = true
let gesture = UILongPressGestureRecognizer(target: self, action: #selector(self.showMenu))
self.addGestureRecognizer(gesture)
}
@objc func showMenu(_ recognizer: UILongPressGestureRecognizer) {
self.becomeFirstResponder()
let menu = UIMenuController.shared
let locationOfTouchInLabel = recognizer.location(in: self)
if !menu.isMenuVisible {
var rect = bounds
rect.origin = locationOfTouchInLabel
rect.size = CGSize(width: 1, height: 1)
menu.showMenu(from: self, rect: rect)
}
}
override func copy(_ sender: Any?) {
let board = UIPasteboard.general
board.string = text
let menu = UIMenuController.shared
menu.setMenuVisible(false, animated: true)
}
override var canBecomeFirstResponder: Bool {
return true
}
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
return action == #selector(UIResponderStandardEditActions.copy)
}
}
在您的故事板中，只需将 UILabel 子类化为 CopyableLabel 类
我在UILabel 上获得了复制和粘贴菜单，我只需要返回YES 以获得canBecomeFirstResponder，然后当所述标签出现在屏幕上时调用[label becomeFirstResponder]。至于从canBecomeFirstResponder返回YES，你可以创建一个自定义的子类或者使用类别修补UILabel：
@implementation UILabel (Clipboard)
- (BOOL) canBecomeFirstResponder
{
return YES;
}
@end
类别解决方案感觉有点老套，但如果您知道自己在做什么，它可能比子类化更容易。我还发布了一个sample project on GitHub，它展示了如何在UILabel 上显示一个简单的粘贴板菜单。
【讨论】：
由于@zoul 的回答，sample project on github 是要走的路。在撰写本文时，该项目实际上并未在剪贴板（粘贴板）上放置任何内容。方法如下：
将此方法的@zoul 实现更改为：
- (void) copy:(id)sender {
UIPasteboard *pboard = [UIPasteboard generalPasteboard];
pboard.string = self.text;
}
【讨论】：
Swift 4 ☻ Xcode 9.2。
通过使用UIMenuController，我们可以做到。
我创建了 IBDesignable 自定义 UILabel 类，您可以直接在情节提要上分配它
@IBDesignable
class TapAndCopyLabel: UILabel {
override func awakeFromNib() {
super.awakeFromNib()
//1.Here i am Adding UILongPressGestureRecognizer by which copy popup will Appears
let gestureRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(handleLongPressGesture(_:)))
self.addGestureRecognizer(gestureRecognizer)
self.isUserInteractionEnabled = true
}
// MARK: - UIGestureRecognizer
@objc func handleLongPressGesture(_ recognizer: UIGestureRecognizer) {
guard recognizer.state == .recognized else { return }
if let recognizerView = recognizer.view,
let recognizerSuperView = recognizerView.superview, recognizerView.becomeFirstResponder()
{
let menuController = UIMenuController.shared
menuController.setTargetRect(recognizerView.frame, in: recognizerSuperView)
menuController.setMenuVisible(true, animated:true)
}
}
//2.Returns a Boolean value indicating whether this object can become the first responder
override var canBecomeFirstResponder: Bool {
return true
}
//3.Here we are enabling copy action
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
return (action == #selector(UIResponderStandardEditActions.copy(_:)))
}
// MARK: - UIResponderStandardEditActions
override func copy(_ sender: Any?) {
//4.copy current Text to the paste board
UIPasteboard.general.string = text
}
}
输出：
【讨论】：
guard recognizer.state == .began else { return } 这样它会在持续时间之后显示菜单控制器，而不是在你抬起手指之后。用户在手指按下时期望得到反馈。
我制作了一个开源 UILabel 子类，它在长按时显示带有“复制”选项的 UIMenuController：
HTCopyableLabel 在 GitHub 上
【讨论】：
如果有人仍然感兴趣，我已经分叉了 zoul 的示例项目并添加了对 ARC（以及其他一些功能）的支持：
https://github.com/zhbrass/UILabel-Clipboard
CopyLabel.h/.m 应该是您要查找的内容
【讨论】：
覆盖UITextField 实例的textFieldShouldBeginEditing 方法，并将其设置为返回NO 以禁用编辑。
查看UITextFieldDelegate 协议了解更多详情。
【讨论】：
在 Swift 5.0 和 Xcode 10.2
中直接在您的 ViewController 中将复制选项添加到您的 UILabel。
//This is your UILabel
@IBOutlet weak var lbl: UILabel!
//In your viewDidLoad()
self.lbl.isUserInteractionEnabled = true
let longPress = UILongPressGestureRecognizer.init(target: self, action: #selector((longPressFunctin(_:))))
self.lbl.addGestureRecognizer(longPress)
//Write these all functions outside the viewDidLoad()
@objc func longPressFunctin(_ gestureRecognizer: UILongPressGestureRecognizer) {
lbl.becomeFirstResponder()
let menu = UIMenuController.shared
if !menu.isMenuVisible {
menu.setTargetRect(CGRect(x: self.lbl.center.x, y: self.lbl.center.y, width: 0.0, height: 0.0), in: view)
menu.setMenuVisible(true, animated: true)
}
}
override func copy(_ sender: Any?) {
let board = UIPasteboard.general
board.string = lbl.text
}
override var canBecomeFirstResponder: Bool {
return true
}
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
return action == #selector(copy(_:))
}
【讨论】：
为了在 SwiftUI 中实现这一点，我们可以使用 pableiros 创建与 UIViewRepresentable 组合的方法。
我们需要对 CopyableLabel 类进行两项更新，因为以下方法在 iOS 13 中已弃用。
.setTargetRect(_,in:)
.setMenutVisible(_,animated)
我们可以改用.showMenu(from:rect:) 方法轻松解决此问题。
这是更新后的CopyableLabel 类。
class CopyableLabel: UILabel {
override init(frame: CGRect) {
super.init(frame: frame)
self.sharedInit()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
self.sharedInit()
}
func sharedInit() {
self.isUserInteractionEnabled = true
self.addGestureRecognizer(UILongPressGestureRecognizer(target: self, action: #selector(self.showMenu)))
}
@objc func showMenu(sender: AnyObject?) {
self.becomeFirstResponder()
let menu = UIMenuController.shared
if !menu.isMenuVisible {
menu.showMenu(from: self, rect: self.bounds) // <- we update the deprecated methods here
}
}
override func copy(_ sender: Any?) {
let board = UIPasteboard.general
board.string = text
let menu = UIMenuController.shared
menu.showMenu(from: self, rect: self.bounds) // <- we update the deprecated methods here
}
override var canBecomeFirstResponder: Bool {
return true
}
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
return action == #selector(UIResponderStandardEditActions.copy)
}
}
然后为了让这个类与 SwiftUI 一起工作，我们所要做的就是创建一个简单的UIViewRepresentable。
struct CopyableLabelView: UIViewRepresentable {
let text: String
private let label = CopyableLabel(frame: .zero)
init(text: String) {
self.text = text
}
func makeUIView(context: Context) -> UILabel {
// Set the text for the label
label.text = text
// Set the content hugging priority so the UILabel's view is
// kept tight to the text.
label.setContentHuggingPriority(.required, for: .horizontal)
label.setContentHuggingPriority(.required, for: .vertical)
return label
}
func updateUIView(_ uiView: UILabel, context: Context) {
// Handle when the text that is passed changes
uiView.text = text
}
}
【讨论】：
如果你有多行文本，你应该使用UITextView
设置委托：
func textView(_ textView: UITextView,
shouldChangeTextIn range: NSRange,
replacementText text: String) -> Bool {
return false
}
它应该可以神奇地工作:)
【讨论】：
保存任何输入：
public class SomeComplexCustomView: UIView {
@IBOutlet var oneOfYourLabels: UILabel!
... your other labels, boxes, etc
public func makeThatLabelCopyable() {
oneOfYourLabels.isUserInteractionEnabled = true
addGestureRecognizer(UITapGestureRecognizer(
target: self, action: #selector(self.copyMenu(sender:))))
addGestureRecognizer(UILongPressGestureRecognizer(
target: self, action: #selector(self.copyMenu(sender:))))
// or use oneOfYourLabels.addGesture... to touch just on that item
}
public override var canBecomeFirstResponder: Bool { return true }
@objc func copyMenu(sender: Any?) {
becomeFirstResponder()
UIMenuController.shared.setTargetRect(bounds, in: self)
// or any exact point you want the pointy box pointing to
UIMenuController.shared.setMenuVisible(true, animated: true)
}
override public func copy(_ sender: Any?) {
UIPasteboard.general.string = oneOfYourLabels.text
// or any exact text you wish
UIMenuController.shared.setMenuVisible(false, animated: true)
}
override public func canPerformAction(
_ action: Selector, withSender sender: Any?) -> Bool {
return (action == #selector(copy(_:)))
}
}
就这么简单！
改善工程的一个细节：
注意我们开启了第一响应者：
public override var canBecomeFirstResponder: Bool { return true }
通常，在带有此类标签的给定屏幕上，您将拥有或不会拥有这样的可复制链接。
所以你很可能会有类似的东西：
var linkTurnedOnCurrently: Bool = false
func doShowThatLink( blah ) {
linkAvailableOnThisScreen = true
... the various code above ...
}
func doShowThatLink( blah ) {
linkAvailableOnThisScreen = false
... perhaps de-color the link, etc ...
}
因此，实际上不是这样：
public override var canBecomeFirstResponder: Bool { return true }
一定要这样做：
public override var canBecomeFirstResponder: Bool {
if linkTurnedOnCurrently { return true }
return super.canBecomeFirstResponder
}
（请注意，它不是类似于“return linkTurnedOnCurrently”。）
【讨论】：
@benvolioT's github project 是非常好的复制示例。对于粘贴，自定义canPerformAction:withSender:。
有关更多信息，请参阅示例 CopyPasteTile。
【讨论】：