在Swift中指定UITextField的最大值

textField.maxLength = 10

class ViewController: UIViewController, UITextFieldDelegate {
    @IBOutlet weak var textField: UITextField!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        textField.delegate = self
    }
    
    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        // 获取当前文本框的文本
        let currentText = textField.text ?? ""
        
        // 计算输入后的文本
        let newText = (currentText as NSString).replacingCharacters(in: range, with: string)
        
        // 检查文本长度是否超过最大值
        if newText.count > 10 {
            return false // 不允许输入
        }
        
        return true // 允许输入
    }
}