Iphone UITextField 仅限整数

使用iPhone开发中的UITextField控件时，有时我们需要限制用户输入的内容只能为整数。这种需求在很多场景下都会出现，比如输入年龄、数量或者其他只能为整数的数据项。本文将介绍如何在UITextField中实现仅限整数的输入限制，并提供相应的代码示例。

textField.delegate = self

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    // 判断用户输入的字符是否为数字
    let allowedCharacters = CharacterSet.decimalDigits
    let characterSet = CharacterSet(charactersIn: string)
    return allowedCharacters.isSuperset(of: characterSet)
}

let pasteboardString = UIPasteboard.general.string
if let _ = pasteboardString {
    let characterSet = CharacterSet(charactersIn: pasteboardString!)
    return allowedCharacters.isSuperset(of: characterSet)
}

swift
import UIKit
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 {
        let allowedCharacters = CharacterSet.decimalDigits
        let characterSet = CharacterSet(charactersIn: string)
        return allowedCharacters.isSuperset(of: characterSet)
    }
    
    @IBAction func textFieldEditingChanged(_ sender: UITextField) {
        // 处理用户输入的整数
        if let text = sender.text, let intValue = Int(text) {
            // 在这里可以对整数进行处理
            print("输入的整数为：\(intValue)")
        }
    }
}