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3
textField.addTarget(self, action: #selector(ViewController.textFieldDidChange(sender:)), for: UIControlEvents.editingChanged)
其他回答
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
}
}
}
您可以在接口生成器中建立此连接。
在故事板中，单击屏幕顶部的助理编辑器(中间的两个圆圈)。 在界面构建器中按Ctrl +单击文本字段。 从EditingChanged拖动到助手视图中的视图控制器类内部。 为函数命名(例如“textDidChange”)，然后单击连接。
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) {
}
