如何检查UITextField何时更改？ [英] How do I check when a UITextField changes?

问题描述

我正在尝试检查文本字段何时更改，相当于textView使用的函数 - textViewDidChange 到目前为止我已经这样做了：

I am trying to check when a text field changes, equivalent too the function used for textView - textViewDidChange so far I have done this:

  func textFieldDidBeginEditing(textField: UITextField) {
        if self.status.text == "" && self.username.text == "" {
            self.topRightButton.enabled = false
        } else {   
            self.topRightButton.enabled = true
        }
    }

哪种工作，但 topRightButton 是在按下文本字段后立即启用，我希望仅在实际输入文本时才启用它？

Which kind of works, but the topRightButton is enabled as soon as the text field is pressed on, I want it to be enabled only when text is actually typed in?

推荐答案

SWIFT

textField.addTarget(self, action: "textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)

然后你可以调用你的函数！

Then you can just call your function!

func textFieldDidChange(textField: UITextField) {
    //your code
}

SWIFT 2.2

textField.addTarget(self, action: #selector(YourViewController.textFieldDidChange(_:)), forControlEvents: UIControlEvents.EditingChanged)

和

func textFieldDidChange(textField: UITextField) {
    //your code
}

SWIFT 3

textField.addTarget(self, action: #selector(textFieldDidChange(_:)), for: .editingChanged)

和

func textFieldDidChange(_ textField: UITextField) {

}

Swift 4

@objc func textFieldDidChange(_ textField: UITextField) {

}

OBJECTIVE-C

[textField addTarget:self action:@selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];

和textFieldDidChange方法是

and textFieldDidChange method is

-(void)textFieldDidChange :(UITextField *) textField{
    //your code
}

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