如何在Swift的TextField中禁用Pasting？

Question

我有一个带有数字键盘的TextField，只有当数字包含数字时，该功能才会运行。

用户崩溃应用的唯一选择是他是否会在TextField中粘贴字母，然后点击确定。

如何在TextField中禁用粘贴？

Answer 1

我同意Leonardo Savio Dabus，如果我是你，我将使用字符串检查并发出警告，这会让事情变得更容易。但是，如果禁用粘贴选项是一个非常想要放入应用程序的奇特功能，那么您需要做更多的工作。我将提供以下步骤。

步骤1：您需要创建另一个扩展UITextField的类。在此示例中，我创建了CustomUITextField。

import Foundation
import UIKit  // don't forget this

class CustomUITextField: UITextField {
    override func canPerformAction(action: Selector, withSender sender: AnyObject?) -> Bool {
        if action == "paste:" {
            return false
        }        
        return super.canPerformAction(action, withSender: sender)
    }
}

第2步：使用ViewController连接故事板。您需要像正常情况一样声明IBOutlet：

@IBOutlet var textFieldA: CustomUITextField?

将@IBOutlet旁边的圆圈连接到情节提要中的textField。那么，这很重要且容易被忽略：

• 转到您的故事板
• 单击目标TextField
• 选择Identity Inspector（第3个）
• 将班级更改为CustomUITextField

下面提供了快照。

那就是它，希望这有效。

<强>信用卡：

主要参考https://teamtreehouse.com/forum/disable-paste-in-uitextfielduitextview-swift

如果您想了解更多关于canPerformAction方法的行为，尽管是Objective-C版本，但是这些概念是共享的：How can I detect that a user has tapped a formatting button in a UIMenuController?

Answer 2

对于 Swift 3 ，它已更改为：

override public func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
    if action == #selector(copy(_:)) || action == #selector(paste(_:)) {
        return false
    }

    return true
}

Answer 3

Swift3

最近添加了

UIResponder​Standard​Edit​Actions（iOS 10.0+），通过它我们可以安全地检查操作是否“粘贴”。

SELECT ID, COL1, COL2 FROM MYTABLE WHERE (? BETWEEN COL1 AND COL2)

Answer 4

详细

• Xcode 9.1，Swift 4
• Xcode 10.2（10E125），Swift 5

解决方案1 ​​

// class TextField: UITextField
extension UITextField {

    open override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
        return action == #selector(UIResponderStandardEditActions.cut) || action == #selector(UIResponderStandardEditActions.copy)
    }
}

解决方案1用法

let textField = UITextField(frame: CGRect(x: 50, y: 120, width: 200, height: 50))
textField.borderStyle = .roundedRect
view.addSubview(textField)

解决方案2

enum ResponderStandardEditActions {
    case cut, copy, paste, select, selectAll, delete
    case makeTextWritingDirectionLeftToRight, makeTextWritingDirectionRightToLeft
    case toggleBoldface, toggleItalics, toggleUnderline
    case increaseSize, decreaseSize

    var selector: Selector {
        switch self {
        case .cut:
            return #selector(UIResponderStandardEditActions.cut)
        case .copy:
            return #selector(UIResponderStandardEditActions.copy)
        case .paste:
            return #selector(UIResponderStandardEditActions.paste)
        case .select:
            return #selector(UIResponderStandardEditActions.select)
        case .selectAll:
            return #selector(UIResponderStandardEditActions.selectAll)
        case .delete:
            return #selector(UIResponderStandardEditActions.delete)
        case .makeTextWritingDirectionLeftToRight:
            return #selector(UIResponderStandardEditActions.makeTextWritingDirectionLeftToRight)
        case .makeTextWritingDirectionRightToLeft:
            return #selector(UIResponderStandardEditActions.makeTextWritingDirectionRightToLeft)
        case .toggleBoldface:
            return #selector(UIResponderStandardEditActions.toggleBoldface)
        case .toggleItalics:
            return #selector(UIResponderStandardEditActions.toggleItalics)
        case .toggleUnderline:
            return #selector(UIResponderStandardEditActions.toggleUnderline)
        case .increaseSize:
            return #selector(UIResponderStandardEditActions.increaseSize)
        case .decreaseSize:
            return #selector(UIResponderStandardEditActions.decreaseSize)
        }
    }

}

class TextField: UITextField {

    var allowedActions: [ResponderStandardEditActions] = [] {
        didSet {
            if !allowedActions.isEmpty && !notAllowedActions.isEmpty {
                notAllowedActions = []
            }
        }
    }

    var notAllowedActions: [ResponderStandardEditActions] = [] {
          didSet {
            if !allowedActions.isEmpty && !notAllowedActions.isEmpty {
                allowedActions = []
            }
        }
    }

    open override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {

        if !allowedActions.isEmpty {
            return allowedActions.map{ $0.selector }.contains(action)
        }

        if !notAllowedActions.isEmpty {
            return !notAllowedActions.map{ $0.selector }.contains(action)
        }
        return super.canPerformAction(action, withSender: sender)
    }
}

解决方案2用法

let textField = TextField(frame: CGRect(x: 50, y: 50, width: 200, height: 50))
textField.borderStyle = .roundedRect
view.addSubview(textField)
textField.allowedActions = [.copy, .cut]
//textField.notAllowedActions = [.copy, .cut]

Answer 5

您可以为UITextField创建扩展程序并覆盖canPerformAction：

override public func canPerformAction(action: Selector, withSender sender: AnyObject?) -> Bool {
        return (action != "paste:") 
}

Answer 6

在实际的swift版本（2.2转到3.0）中，此功能代码必须重构为：

override public func canPerformAction(action: Selector, withSender sender: AnyObject?) -> Bool {
    if action == #selector(NSObject.copy(_:)) || action == #selector(NSObject.paste(_:)) {
        return false
    }

    return true
}

Answer 7

迅速4.1，此代码可与ViewController一起正常工作。

1）禁用所有选项（复制，粘贴，删除...等）

extension UITextField {

    open override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
        return false
    }
}

2）启用特定选项（选择，全选...等等）

extension UITextField {

open override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
    return action == #selector(UIResponderStandardEditActions.select(_:)) || action == #selector(UIResponderStandardEditActions.selectAll(_:))
}

Answer 8

您可以将IBAction附加到文本字段的已发送事件（编辑已更改），以便在键入时从字符串中过滤非数字：

@IBAction func changedTextAction(sender: UITextField) {
    sender.text = String(Array(sender.text).map{String($0)}.filter{ $0.toInt() != nil }.map{Character($0)} )
}

Answer 9

class CustomUITextField: UITextField {
    override public func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
        if action == #selector(cut(_:)) ||
           action == #selector(copy(_:)) ||  
           action == #selector(UIResponderStandardEditActions.paste(_:)) || 
           action == #selector(UIResponderStandardEditActions.select(_:)) || 
           action == #selector(UIResponderStandardEditActions.selectAll(_:)) || 
           action == #selector(UIResponderStandardEditActions.delete(_:)) ||  
           action == #selector(UIResponderStandardEditActions.makeTextWritingDirectionLeftToRight(_:)) ||  
           action == #selector(UIResponderStandardEditActions.makeTextWritingDirectionRightToLeft(_:)) || 
           action == #selector(UIResponderStandardEditActions.toggleBoldface(_:)) || 
           action == #selector(UIResponderStandardEditActions.toggleItalics(_:)) || 
           action == #selector(UIResponderStandardEditActions.toggleUnderline(_:)) || 
           action == #selector(UIResponderStandardEditActions.increaseSize(_:)) || 
           action == #selector(UIResponderStandardEditActions.decreaseSize(_:)) 
        {
             return false
        };
        return true
    }
}

Answer 10

我为textField创建了一个自定义类。我想在文本字段上启用/禁用操作时处理了这种情况。您可以根据自己的要求自定义代码。设置isActionsEnabled true / false以启用/禁用textfield上的操作。

喜欢使用

  

返回super.canPerformAction（action，withSender：sender）

而不是

  

返回true

因为在某些情况下返回true可能会导致崩溃。

这是我的代码，

open class MyTextFieldEffect : UITextField {

    var isActionsEnabled = true {
        didSet {
            reloadInputViews()
        }
    }

override open func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
        /* disable particular actions
        if (action == #selector(paste(_:)) || action == #selector(copy(_:)) || action == #selector(select(_:)) || action == #selector(cut(_:)) || action == #selector(delete(_:)) || action == #selector(replace(_:withText:))  || action == #selector(select(_:))  || action == #selector(selectAll(_:)) || action == #selector(insertText(_:)) || action == #selector(draw(_:))) && !isActionsEnabled {
            return false
        }
        return super.canPerformAction(action, withSender: sender)
                                           */

       //disable all actions
        if !isActionsEnabled {
            return false
        }

        return super.canPerformAction(action, withSender: sender)
    }
}

Answer 11

快速5

如果您想阻止应用程序中每个文本字段的粘贴操作

extension UITextField {
    override open func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
        return action == #selector(UIResponderStandardEditActions.paste(_:)) ?
            false : super.canPerformAction(action, withSender: sender)
    }
}

编辑

如果要阻止将选择器作为输入视图的文本字段的粘贴操作，请添加guard，如下所示：

extension UITextField {
    override open func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
        guard inputView != nil else { return super.canPerformAction(action, withSender: sender) }

        return action == #selector(UIResponderStandardEditActions.paste(_:)) ?
            false : super.canPerformAction(action, withSender: sender)
    }
}

警告：第二种解决方案将允许用户粘贴在数字字段上。

Answer 12

使用代码进行小编辑，因为当您尝试使用剪切或其他任何功能时，应用程序将崩溃。以下代码在swift 3上测试并且运行良好

override public func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
        if action == #selector(copy(_:)) || action == #selector(paste(_:)) {
            return false
        }
        return super.canPerformAction(action, withSender: sender)
    }

Answer 13

如果要在TEXTFIELD上打开日期选择器或选择器视图，请单击下面的代码。

在您的课程中添加以下两个方法。

//Hide Menu View
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {

    if YOURTEXTFIELD.isFirstResponder {
        DispatchQueue.main.async(execute: {
            (sender as? UIMenuController)?.setMenuVisible(false, animated: false)
        })
        return false
    }

    return super.canPerformAction(action, withSender: sender)
}

//必须实施

func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
            return false
}

Answer 14

我确实使用了这段代码。工作正常。

override func canPerformAction(_ action: Selector, withSender sender: Any?)  Bool {

    if YOURTEXTFIELD.isFirstResponder {
        DispatchQueue.main.async(execute: {
            (sender as? UIMenuController)?.setMenuVisible(false, animated: false)
        })
        return false
    }

    return super.canPerformAction(action, withSender: sender)
}