Swift - UIAlertController基本用法

func testAlert(){
let alertController = UIAlertController(title: "提示", message: "确定要离开该页面吗?", preferredStyle: .alert)
let cancelAction = UIAlertAction(title: "取消", style: .cancel, handler: nil);
let okAction = UIAlertAction(title: "确定", style: .default) { (action) in
print("点击了确定")
}
alertController.addAction(cancelAction)
alertController.addAction(okAction)
self.present(alertController, animated: true, completion: nil)
}

func testSheet(){
let alertController = UIAlertController(title: "保存或删除数据", message: "删除数据后无法恢复", preferredStyle: .actionSheet)
let cancelAction = UIAlertAction(title: "取消", style: .cancel, handler: nil)
let saveAction = UIAlertAction(title: "保存", style: .default, handler: nil)
let deleteAction = UIAlertAction(title: "删除", style: .destructive, handler: nil)
alertController.addAction(cancelAction)
alertController.addAction(saveAction)
alertController.addAction(deleteAction)
self.present(alertController, animated: true, completion: nil)
}

func testTextFieldAlert(){
let alertController = UIAlertController(title: "新建文件夹", message: "请输入文件夹名称", preferredStyle: .alert)
alertController.addTextField { (textField) in
textField.placeholder = "新建文件夹名称"
}
let cancelAction = UIAlertAction(title: "取消", style: .cancel, handler: nil)
let okAction = UIAlertAction(title: "好的", style: .default, handler: nil)
alertController.addAction(cancelAction)
alertController.addAction(okAction)
self.present(alertController, animated: true, completion: nil)

}

func testMessage(){
let alertController = UIAlertController(title: "保存成功", message: nil, preferredStyle: .alert)
// 显示提示框
self.present(alertController, animated: true, completion: nil)
// 两秒钟后自动消失
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 2) {
self.presentedViewController?.dismiss(animated: true, completion: nil)
}
}

附：扩展 UIAlertController

import UIKit
extension UIAlertController {
// 在指定视图控制器上弹出普通消息提示框
static func showAlert(message:String,in viewController:UIViewController) {
let alert = UIAlertController(title: nil, message: message, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "确定", style: .cancel, handler: nil))
viewController.present(alert, animated: true, completion: nil)
}

// 在根视图控制器上弹出普通消息提示框
static func showAlert(message:String){
if let vc = UIApplication.shared.keyWindow?.rootViewController {
showAlert(message: message, in: vc)
}
}

// 在指定视图匡子强上弹出确认框
static func showConfirm(message:String,in viewController:UIViewController,confirm:@escaping (UIAlertAction) -> Void){
let alert = UIAlertController(title: nil, message: message, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "取消", style: .cancel, handler: nil))
alert.addAction(UIAlertAction(title: "确定", style: .default, handler: confirm))
viewController.present(alert, animated: true, completion: nil)
}

// 在根视图控制器上弹出确认框
static func showConfirm(message:String, confirm:@escaping (UIAlertAction) -> Void){
if let vc = UIApplication.shared.keyWindow?.rootViewController {
showConfirm(message: message, in: vc, confirm: confirm)
}
}
}

调用方法

UIAlertController.showConfirm(message: “保存数据”, in: self) { (action) in

print(“点击了确认”)

}

参考链接