Question

我想通过userInfo将参数传递给以下函数，因为该函数必须在延迟后执行。

func showAlert(alertTitle: String, withMessage alertMessage: String, fromController controller: UIViewController) {
     //do stuff...
}

已经延迟完成了那部分，但我不知道如何将多个参数发送到showAlert.的正文

func fireTimer() {
   timer = NSTimer.scheduledTimerWithTimeInterval(4, target: self, selector: Selector("showAlert:"), userInfo: nil, repeats: false)
}

非常感谢您的协助。

我仍然遇到错误，不知道为什么。

无法识别的选择器发送到实例

这就是我的代码的样子。怎么了？

class AlertController: UIAlertController {  
var timer = NSTimer()

func showAlert(alertTitle: String, withMessage alertMessage: String, fromController controller: UIViewController)
{
    var alert = UIAlertController(title: alertTitle, message: alertMessage, preferredStyle: .Alert)
    controller.presentViewController(alert, animated: true, completion: nil)
}

func showAlert2(dict: [String: AnyObject])
{
    showAlert(dict["title"] as! String,
        withMessage: dict["message"] as! String,
        fromController: dict["controller"] as! UIViewController)
}

func fireTimer(title: String, message: String, viewController: UIViewController)
{
    timer = NSTimer.scheduledTimerWithTimeInterval(4, target: self, selector: Selector("showAlert2:"), userInfo: ["title":title, "message": message, "controller": viewController], repeats: false)
}

Answer 1

您不能使用NSTimer传递多个参数，但是，您可以将该参数设置为数组或ditionary或类似参数。

然后创建一个新函数，该函数接受该数组/字典，然后使用数组/字典中的每个参数调用函数

func fireTimer() {
    timer = NSTimer.scheduledTimerWithTimeInterval(4, target: self, selector: Selector("showAlert2:"), userInfo: ["title":"a title", "message": "a message", "controller": controller], repeats: false)
}

func showAlert2(timer: NSTimer) {   
    let dict = timer.userInfo as NSDictionary

    showAlert(dict["title"] as String, wwithMessage: dict["message"] as String, fromController: dict["controller"] as UIViewController)
}

func showAlert(alertTitle: String, withMessage alertMessage: String, fromController controller: UIViewController) {
//    do stuff...
}

NSTimer选择器中的多个参数

1 个答案: