Question

您好我写了一些代码（使用swift）：

import UIKit
import Foundation

func timerFireMethod(timer1: NSTimer) { }

class ViewController: UIViewController {

    func timerFireMethod(timer1: NSTimer) { }
    var greytitle : UIImage = UIImage(named:"AppTitle.png")
    var redtitle : UIImage = UIImage(named:"AppTitleRed.png")

    @IBOutlet var maintitle: UIImageView

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib

         class func scheduledTimerWithTimeInterval(_ seconds: NSTimeInterval = 0.1,
            target timer1m: AnyObject!,
            selector timer1: Selector,
            userInfo nil: AnyObject!,
            repeats true: Bool) -> NSTimer!

        maintitle.image = greytitle

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

如果它说class func，我会收到错误

"Class Methods may only be declared on a type"

我知道这是一个非常新手的问题，但如果有人能解释我做错了什么，我将不胜感激！另外我注意到4行作为代码被高举，但它们是代码。

Answer 1

您的问题是您正在尝试在另一个方法（timerWithInterval）中编写方法（viewDidLoad）。您也没有以正确的方式创建计时器。我看到你声明了一个类函数来做这个，所以我将以此为例。这样做：

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib


}
class func scheduledTimerWithTimeInterval(_ seconds: NSTimeInterval = 0.1,
        target timer1m: AnyObject!,
        selector timer1: Selector,
        userInfo nil: AnyObject!,
        repeats doesRepeat: Bool) -> NSTimer!{

    //maintitle.image = greytitle
    var timer = NSTimer.scheduledTimerWithTimeInterval(seconds, target: timer1m, selector: timer1, userInfo: nil, repeats:doesRepeat)
    (NSRunLoop.currentRunLoop()).addTimer(timer, forMode:NSDefaultRunLoopMode)
}

Answer 2

要创建计时器，您应该使用

var timer = NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: "someFunction", userInfo: nil, repeats: false)

错误：类方法只能在类型上声明

2 个答案: