iphone - UITextField 值更改事件？

Question

如何才能在文本字段的内容发生更改时调用函数？

Answer 1

Objective-C

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

swift 4

myTextField.addTarget(self, action: #selector(textFieldDidChange(sender:)), for: .editingChanged)

@objc func textFieldDidChange(sender: UITextField) {...}