I've got a TextField with a number pad and the function runs only if it contains numbers.
The only option that the user will crash the app is if he will paste letters in the TextField and click OK.
How can I disable pasting in the TextField?
I agree with Leonardo Savio Dabus, if I were you I'll use string checking and just give out a warning, it makes things easier. BUT, if disabling paste option is a fancy feature you really want to put into your app, then you need to do more work. I'll provide the steps below.
Step 1: You need to create another class which extends the UITextField. In this example, I made my 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)
}
}
Step 2: Wire the storyboard with your ViewController. You need to declare an IBOutlet as in normal case:
@IBOutlet var textFieldA: CustomUITextField?
Wire the circle next to the @IBOutlet to the textField in the storyboard. THEN, this is important and easy to be ignored:
- Go to your storyboard
- Click the target TextField
- Select Identity Inspector (the 3rd one)
- Change the class as CustomUITextField
Quick snapshot is provided below.
That's it, hope this works.
Credit:
Mainly reference from https://teamtreehouse.com/forum/disable-paste-in-uitextfielduitextview-swift
If you want to know more about the behavior of canPerformAction method, though is objective-C version, but the concepts are shared: How can I detect that a user has tapped a formatting button in a UIMenuController?
For Swift 3 it's changed to:
override public func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
if action == #selector(copy(_:)) || action == #selector(paste(_:)) {
return false
}
return true
}
For Swift3
UIResponderStandardEditActions has been added recently (iOS 10.0+) through which we can safely check if action is "paste" or not.
import UIKit
class NMTextField: UITextField {
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
if action == #selector(UIResponderStandardEditActions.paste(_:)) {
return false
}
return super.canPerformAction(action, withSender: sender)
}
}
Details
- Xcode 9.1, Swift 4
- Xcode 10.2 (10E125), Swift 5
Solution 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)
}
}
Solution 1 usage
let textField = UITextField(frame: CGRect(x: 50, y: 120, width: 200, height: 50))
textField.borderStyle = .roundedRect
view.addSubview(textField)
Solution 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)
}
}
Solution 2 usage
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]
You can create an extension for UITextField and override canPerformAction:
override public func canPerformAction(action: Selector, withSender sender: AnyObject?) -> Bool {
return (action != "paste:")
}
In the actual swift version(2.2 going to 3.0) this function code must be refactored to:
override public func canPerformAction(action: Selector, withSender sender: AnyObject?) -> Bool {
if action == #selector(NSObject.copy(_:)) || action == #selector(NSObject.paste(_:)) {
return false
}
return true
}
Swift 4.1 this code is working fine with ViewController.
1) Disable all option (copy, paste, delete.....etc)
extension UITextField {
open override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
return false
}
}
2) Enable particular option (select, selectAll... etc)
extension UITextField {
open override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
return action == #selector(UIResponderStandardEditActions.select(_:)) || action == #selector(UIResponderStandardEditActions.selectAll(_:))
}
You can just attach an IBAction to your Sent Events (editing changed) of your textfield to filter non numbers out of your string as you type as follow:
@IBAction func changedTextAction(sender: UITextField) {
sender.text = String(Array(sender.text).map{String($0)}.filter{ $0.toInt() != nil }.map{Character($0)} )
}
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
}
}
I have created a custom class for textField. I have handled the case when you want to enable/disable actions on textfield. You can customize the code as per your requirement. Set isActionsEnabled true/false for enable/disable actions on textfield.
Prefer to use
return super.canPerformAction(action, withSender: sender)
instead of
return true
because returning true might cause a crash in some cases.
Here is my code,
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)
}
}
Small edit with a code because when you try to use any function like cut or another one the app will crash . The following code tested on swift 3 and working very well
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)
}
If you want to Open Date Picker or Picker view on TEXTFIELD click then below code work.
Add below two methods in your class.
//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)
}
//MUST Implement
func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
return false
}
来源：https://stackoverflow.com/questions/29596043/how-to-disable-pasting-in-a-textfield-in-swift