我试图检查当一个文本字段发生变化时，等效于textView - textViewDidChange的函数，到目前为止我已经做到了这一点:
func textFieldDidBeginEditing(textField: UITextField) {
if self.status.text == "" && self.username.text == "" {
self.topRightButton.enabled = false
} else {
self.topRightButton.enabled = true
}
}
哪种类型的工作，但topRightButton一经文本字段被按下就被启用，我想它只在文本实际输入时才被启用?
当前回答
你应该遵循以下步骤:
对文本框进行Outlet引用 AssignUITextFieldDelegate给控制器类 配置yourTextField.delegate 实现你需要的任何函数
示例代码:
import UIKit
class ViewController: UIViewController, UITextFieldDelegate {
@IBOutlet var yourTextFiled : UITextField!
override func viewDidLoad() {
super.viewDidLoad()
yourTextFiled.delegate = self
}
func textFieldDidEndEditing(_ textField: UITextField) {
// your code
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
// your code
}
.
.
.
}
其他回答
现在在iOS13+上有一个UITextField委托方法可用
optional func textFieldDidChangeSelection(_ textField: UITextField)
到目前为止我处理它的方式:在UITextFieldDelegate中
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool
{
// text hasn't changed yet, you have to compute the text AFTER the edit yourself
let updatedString = (textField.text as NSString?)?.stringByReplacingCharactersInRange(range, withString: string)
// do whatever you need with this updated string (your code)
// always return true so that changes propagate
return true
}
Swift4版本
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let updatedString = (textField.text as NSString?)?.replacingCharacters(in: range, with: string)
return true
}
你可以通过“shouldchangecharter”委托或者“begin and end”文本字段委托来管理编辑。别忘了设置委托
我设法做到这一点使用“did开始和结束编辑”下面。
//MARK:- TextViewDelegate
extension ViewController: UITextFieldDelegate {
func textFieldDidEndEditing(_ textField: UITextField) {
let count = self.tfEmail.text?.count ?? 0
if textField == self.tfEmail {
if count == 0{
//Empty textfield
}else{
//Non-Empty textfield
}
}
}
func textFieldDidBeginEditing(_ textField: UITextField) {
if textField == self.tfEmail{
//when user taps on textfield
}
}
}
斯威夫特3
textField.addTarget(self, action: #selector(ViewController.textFieldDidChange(sender:)), for: UIControlEvents.editingChanged)
这是如何使用Swift 3添加textField文本更改监听器:
将你的类声明为UITextFieldDelegate
override func viewDidLoad() {
super.viewDidLoad()
textField.delegate = self
textField.addTarget(self, action: #selector(UITextFieldDelegate.textFieldShouldEndEditing(_:)), for: UIControlEvents.editingChanged)
}
然后只是传统地添加一个textFieldShouldEndEditing函数:
func textFieldShouldEndEditing(_ textField: UITextField) -> Bool { // do stuff
return true
}
