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
斯威夫特4.2
把这个写在viewDidLoad中
// to detect if TextField changed
TextField.addTarget(self, action: #selector(textFieldDidChange(_:)),
for: UIControl.Event.editingChanged)
把这个写在viewDidLoad外面
@objc func textFieldDidChange(_ textField: UITextField) {
// do something
}
你可以通过uicontrol。event。editingdidbegin改变事件或者任何你想检测的东西。
其他回答
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
}
textField(_:shouldChangeCharactersIn:replacementString:)在Xcode 8中为我工作，Swift 3如果你想检查每一个按键。
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
// Whatever code you want to run here.
// Keep in mind that the textfield hasn't yet been updated,
// so use 'string' instead of 'textField.text' if you want to
// access the string the textfield will have after a user presses a key
var statusText = self.status.text
var usernameText = self.username.text
switch textField{
case self.status:
statusText = string
case self.username:
usernameText = string
default:
break
}
if statusText == "" && usernameText == "" {
self.topRightButton.enabled = false
} else {
self.topRightButton.enabled = true
}
//Return false if you don't want the textfield to be updated
return true
}
斯威夫特5.0
textField.addTarget(self, action: #selector(ViewController.textFieldDidChange(_:)),
for: .editingChanged)
及处理方法:
@objc func textFieldDidChange(_ textField: UITextField) {
}
斯威夫特4.0
textField.addTarget(self, action: #selector(ViewController.textFieldDidChange(_:)),
for: UIControlEvents.editingChanged)
及处理方法:
@objc func textFieldDidChange(_ textField: UITextField) {
}
斯威夫特3.0
textField.addTarget(self, action: #selector(textFieldDidChange(textField:)), for: .editingChanged)
及处理方法:
func textFieldDidChange(textField: UITextField) {
}
斯威夫特4
在viewDidLoad ():
//ADD BUTTON TO DISMISS KEYBOARD
// Init a keyboard toolbar
let toolbar = UIView(frame: CGRect(x: 0, y: view.frame.size.height+44, width: view.frame.size.width, height: 44))
toolbar.backgroundColor = UIColor.clear
// Add done button
let doneButt = UIButton(frame: CGRect(x: toolbar.frame.size.width - 60, y: 0, width: 44, height: 44))
doneButt.setTitle("Done", for: .normal)
doneButt.setTitleColor(MAIN_COLOR, for: .normal)
doneButt.titleLabel?.font = UIFont(name: "Titillium-Semibold", size: 13)
doneButt.addTarget(self, action: #selector(dismissKeyboard), for: .touchUpInside)
toolbar.addSubview(doneButt)
USDTextField.inputAccessoryView = toolbar
增加这个函数:
@objc func dismissKeyboard() {
//Causes the view (or one of its embedded text fields) to resign the first responder status.
view.endEditing(true)
}
Swift 3.0.1+(其他一些Swift 3.0的答案不是最新的)
textField.addTarget(self, action: #selector(ViewController.textFieldDidChange(_:)),
for: UIControlEvents.editingChanged)
func textFieldDidChange(_ textField: UITextField) {
}
