我一直在努力创建一个UIAlertView在Swift，但由于某种原因，我不能得到正确的声明，因为我得到这个错误:
无法找到一个超载的'init'接受提供的 参数
我是这样写的:
let button2Alert: UIAlertView = UIAlertView(title: "Title", message: "message",
delegate: self, cancelButtonTitle: "OK", otherButtonTitles: nil)
然后我使用:
button2Alert.show()
到目前为止，它正在崩溃，我只是不能得到正确的语法。
当前回答
// UIAlertView的自定义类
//MARK:- MODULES
import Foundation
import UIKit
//MARK:- CLASS
class Alert : NSObject{
static let shared = Alert()
var okAction : AlertSuccess?
typealias AlertSuccess = (()->())?
var alert: UIAlertController?
/** show */
public func show(title : String?, message : String?, viewController : UIViewController?, okAction : AlertSuccess = nil) {
let version : NSString = UIDevice.current.systemVersion as NSString
if version.doubleValue >= 8 {
alert = UIAlertController(title: title, message: message, preferredStyle:.alert)
alert?.addAction(UIAlertAction(title: "OK", style: .default, handler: { (action: UIAlertAction) in
if let okAction = okAction {
okAction()
}
}))
viewController?.present(alert ?? UIAlertController(), animated:true, completion:nil);
}
}
/** showWithCancelAndOk */
public func showWithCancelAndOk(title : String, okTitle : String, cancelTitle : String, message : String, viewController : UIViewController?, okAction : AlertSuccess = nil, cancelAction : AlertSuccess = nil) {
let version:NSString = UIDevice.current.systemVersion as NSString;
if version.doubleValue >= 8 {
alert = UIAlertController(title: title, message: message, preferredStyle:.alert)
alert?.addAction(UIAlertAction(title: cancelTitle, style: .default, handler: { (action: UIAlertAction) in
if let cancelAction = cancelAction {
cancelAction()
}
}))
alert?.addAction(UIAlertAction(title: okTitle, style: .default, handler: { (action: UIAlertAction) in
if let okAction = okAction {
okAction()
}
}))
viewController?.present(alert!, animated:true, completion:nil);
}
}
/** showWithTimer */
public func showWithTimer(message : String?, viewController : UIViewController?) {
let version : NSString = UIDevice.current.systemVersion as NSString
if version.doubleValue >= 8 {
alert = UIAlertController(title: "", message: message, preferredStyle:.alert)
viewController?.present(alert ?? UIAlertController(), animated:true, completion:nil)
let when = DispatchTime.now() + 1
DispatchQueue.main.asyncAfter(deadline: when){
self.alert?.dismiss(animated: true, completion: nil)
}
}
}
}
使用:
Alert.shared.show(title: "No Internet Connection", message: "The internet connection appers to be offline.", viewController: self) //without ok action
Alert.shared.show(title: "No Internet Connection", message: "The internet connection appers to be offline.", viewController: self, okAction: {
//ok action
}) // with ok action
Alert.shared.show(title: "No Internet Connection", message: "The internet connection appers to be offline.", viewController: self, okAction: {
//ok action
}, cancelAction: {
//cancel action
}) //with cancel and ok action
Alert.shared.showWithTimer(message : "This is an alert with timer", viewController : self) //with timer
其他回答
一个按钮
class ViewController: UIViewController {
@IBAction func showAlertButtonTapped(_ sender: UIButton) {
// create the alert
let alert = UIAlertController(title: "My Title", message: "This is my message.", preferredStyle: UIAlertController.Style.alert)
// add an action (button)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertAction.Style.default, handler: nil))
// show the alert
self.present(alert, animated: true, completion: nil)
}
}
两个按钮
class ViewController: UIViewController {
@IBAction func showAlertButtonTapped(_ sender: UIButton) {
// create the alert
let alert = UIAlertController(title: "UIAlertController", message: "Would you like to continue learning how to use iOS alerts?", preferredStyle: UIAlertController.Style.alert)
// add the actions (buttons)
alert.addAction(UIAlertAction(title: "Continue", style: UIAlertAction.Style.default, handler: nil))
alert.addAction(UIAlertAction(title: "Cancel", style: UIAlertAction.Style.cancel, handler: nil))
// show the alert
self.present(alert, animated: true, completion: nil)
}
}
三个按钮
class ViewController: UIViewController {
@IBAction func showAlertButtonTapped(_ sender: UIButton) {
// create the alert
let alert = UIAlertController(title: "Notice", message: "Lauching this missile will destroy the entire universe. Is this what you intended to do?", preferredStyle: UIAlertController.Style.alert)
// add the actions (buttons)
alert.addAction(UIAlertAction(title: "Remind Me Tomorrow", style: UIAlertAction.Style.default, handler: nil))
alert.addAction(UIAlertAction(title: "Cancel", style: UIAlertAction.Style.cancel, handler: nil))
alert.addAction(UIAlertAction(title: "Launch the Missile", style: UIAlertAction.Style.destructive, handler: nil))
// show the alert
self.present(alert, animated: true, completion: nil)
}
}
处理按钮
在上面的例子中，处理程序为nil。当用户点击按钮时，你可以用一个闭包来替换nil。例如:
alert.addAction(UIAlertAction(title: "Launch the Missile", style: UIAlertAction.Style.destructive, handler: { action in
// do something like...
self.launchMissile()
}))
笔记
多个按钮不一定需要使用不同的UIAlertAction。风格类型。它们都可以是。default。 对于超过三个按钮，可以考虑使用动作表。设置非常相似。这里有一个例子。
我还有一招。假设您有5个类，其中要应用注销警报。尝试使用swift类扩展。
文件-新建- Swift类-命名。
增加如下内容:
public extension UIViewController
{
func makeLogOutAlert()
{
var refreshAlert = UIAlertController(title: "Log Out", message: "Are You Sure to Log Out ? ", preferredStyle: UIAlertControllerStyle.Alert)
refreshAlert.addAction(UIAlertAction(title: "Confirm", style: .Default, handler: { (action: UIAlertAction!) in
self.navigationController?.popToRootViewControllerAnimated(true)
}))
refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .Default, handler: { (action: UIAlertAction!) in
refreshAlert .dismissViewControllerAnimated(true, completion: nil)
}))
presentViewController(refreshAlert, animated: true, completion: nil)
}
}
实现使用:self.makeLogOutAlert()。希望能有所帮助。
如果你的目标是iOS 7和8，你需要这样的东西来确保你对每个版本都使用了正确的方法，因为UIAlertView在iOS 8中已弃用，但UIAlertController在iOS 7中不可用:
func alert(title: String, message: String) {
if let getModernAlert: AnyClass = NSClassFromString("UIAlertController") { // iOS 8
let myAlert: UIAlertController = UIAlertController(title: title, message: message, preferredStyle: .Alert)
myAlert.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil))
self.presentViewController(myAlert, animated: true, completion: nil)
} else { // iOS 7
let alert: UIAlertView = UIAlertView()
alert.delegate = self
alert.title = title
alert.message = message
alert.addButtonWithTitle("OK")
alert.show()
}
}
// UIAlertView的自定义类
//MARK:- MODULES
import Foundation
import UIKit
//MARK:- CLASS
class Alert : NSObject{
static let shared = Alert()
var okAction : AlertSuccess?
typealias AlertSuccess = (()->())?
var alert: UIAlertController?
/** show */
public func show(title : String?, message : String?, viewController : UIViewController?, okAction : AlertSuccess = nil) {
let version : NSString = UIDevice.current.systemVersion as NSString
if version.doubleValue >= 8 {
alert = UIAlertController(title: title, message: message, preferredStyle:.alert)
alert?.addAction(UIAlertAction(title: "OK", style: .default, handler: { (action: UIAlertAction) in
if let okAction = okAction {
okAction()
}
}))
viewController?.present(alert ?? UIAlertController(), animated:true, completion:nil);
}
}
/** showWithCancelAndOk */
public func showWithCancelAndOk(title : String, okTitle : String, cancelTitle : String, message : String, viewController : UIViewController?, okAction : AlertSuccess = nil, cancelAction : AlertSuccess = nil) {
let version:NSString = UIDevice.current.systemVersion as NSString;
if version.doubleValue >= 8 {
alert = UIAlertController(title: title, message: message, preferredStyle:.alert)
alert?.addAction(UIAlertAction(title: cancelTitle, style: .default, handler: { (action: UIAlertAction) in
if let cancelAction = cancelAction {
cancelAction()
}
}))
alert?.addAction(UIAlertAction(title: okTitle, style: .default, handler: { (action: UIAlertAction) in
if let okAction = okAction {
okAction()
}
}))
viewController?.present(alert!, animated:true, completion:nil);
}
}
/** showWithTimer */
public func showWithTimer(message : String?, viewController : UIViewController?) {
let version : NSString = UIDevice.current.systemVersion as NSString
if version.doubleValue >= 8 {
alert = UIAlertController(title: "", message: message, preferredStyle:.alert)
viewController?.present(alert ?? UIAlertController(), animated:true, completion:nil)
let when = DispatchTime.now() + 1
DispatchQueue.main.asyncAfter(deadline: when){
self.alert?.dismiss(animated: true, completion: nil)
}
}
}
}
使用:
Alert.shared.show(title: "No Internet Connection", message: "The internet connection appers to be offline.", viewController: self) //without ok action
Alert.shared.show(title: "No Internet Connection", message: "The internet connection appers to be offline.", viewController: self, okAction: {
//ok action
}) // with ok action
Alert.shared.show(title: "No Internet Connection", message: "The internet connection appers to be offline.", viewController: self, okAction: {
//ok action
}, cancelAction: {
//cancel action
}) //with cancel and ok action
Alert.shared.showWithTimer(message : "This is an alert with timer", viewController : self) //with timer
在IOS 9上，你可以这样做
let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
