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

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。

我已经做了一个单例类,以便从应用程序的任何地方使用:https://github.com/Swinny1989/Swift-Popups

然后你可以创建一个带有多个按钮的弹出窗口,如下所示:

Popups.SharedInstance.ShowAlert(self, title: "Title goes here", message: "Messages goes here", buttons: ["button one" , "button two"]) { (buttonPressed) -> Void in
    if buttonPressed == "button one" { 
      //Code here
    } else if buttonPressed == "button two" {
        // Code here
    }
}

或者弹出一个按钮,像这样:

Popups.SharedInstance.ShowPopup("Title goes here", message: "Message goes here.")

或者这样做

        let alert = UIAlertController(title: "Alert", message: "Saved Successfully", preferredStyle: UIAlertController.Style.alert)
        alert.addAction(UIAlertAction(title: "Ok", style: UIAlertAction.Style.default, handler: nil))
        self.present(alert, animated: true, completion: nil)

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)

对于SWIFT4,我认为扩展UIViewController并创建一个可重用的确认控件是最优雅的方式。

你可以像下面这样扩展UIViewController:

extension UIViewController {

func AskConfirmation (title:String, message:String, completion:@escaping (_ result:Bool) -> Void) {
    let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)
    self.present(alert, animated: true, completion: nil)

    alert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { action in
        completion(true)
    }))

    alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { action in
        completion(false)
    }))
  }
}

那么你可以随时使用它:

 AskConfirmation(title: "YOUR MESSAGE TITLE", message: "YOUR MESSAGE") { (result) in
        if result { //User has clicked on Ok

        } else { //User has clicked on Cancel

        }
    }