import UIKit
class ViewController: UIViewController ,UIActionSheetDelegate{
@IBAction func btn1(_ sender: UIButton) {
label1.text="文本显示"
let alertController = UIAlertController(title: "修改文本", message: nil, preferredStyle: UIAlertControllerStyle.alert)
alertController.addTextField(configurationHandler: { (textField: UITextField!) -> Void in
textField.placeholder = "请输入内容"
// 添加监听代码，监听文本框变化时要做的操作
NotificationCenter.default.addObserver(self, selector: #selector(self.alertTextFieldDidChange), name: NSNotification.Name.UITextFieldTextDidChange, object: textField)
})
let cancelAction = UIAlertAction(title: "取消", style: UIAlertActionStyle.cancel, handler: nil)
let okAction = UIAlertAction(title: "确认", style: UIAlertActionStyle.default , handler: { (action: UIAlertAction!) -> Void in
let login = (alertController.textFields?.first)! as UITextField
let str = login.text
self.label1.text=str
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UITextFieldTextDidChange, object: nil)
})
okAction.isEnabled = false
alertController.addAction(cancelAction)
alertController.addAction(okAction)
self.present(alertController, animated: true, completion: nil)
}
/// 监听文字改变
@objc func alertTextFieldDidChange(){
let alertController = self.presentedViewController as! UIAlertController?
if (alertController != nil) {
let login = (alertController!.textFields?.first)! as UITextField
let okAction = alertController!.actions.last! as UIAlertAction
if (!(login.text?.isEmpty)!) {
okAction.isEnabled = true
} else {
okAction.isEnabled = false
}
}
}
@IBOutlet weak var label1: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
@IBOutlet weak var hello: UILabel!
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
效果图
//
// ViewController.swift
// hello
//
// Created by loaderman on 2018/12/22.
// Copyright © 2018年 loaderman. All rights reserved.
// import UIKit class ViewController: UIViewController ,UIActionSheetDelegate{
@IBAction func btn1(_ sender: UIButton) { weak var weakSelf = self // 弱引用
let alertController = UIAlertController()
let cancelAction = UIAlertAction(title: "取消", style: .cancel, handler: nil)
let directMessagesAction = UIAlertAction(title: "私信", style: .default) { (action) in
self.label1.text="私信"
}
let focusOnAction = UIAlertAction(title: "关注", style: .default) { (action) in
self.label1.text="关注"
}
alertController.addAction(focusOnAction)
alertController.addAction(directMessagesAction)
alertController.addAction(cancelAction)
weakSelf!.present(alertController, animated: true, completion: nil)
} @IBOutlet weak var label1: UILabel! override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
@IBOutlet weak var hello: UILabel! override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
} }
效果