Swift - Timer - Versionsgeschichte

134.3.86.14 am 29. Dezember 2022 um 15:10 Uhr

2022-12-29T15:10:41Z

134.3.86.14: /* Timer mit Startzeitpunkt */

2022-12-29T15:06:27Z

Timer mit Startzeitpunkt

134.3.86.14: /* Beispiel 2 */

2022-12-29T15:05:47Z

Beispiel 2

134.3.86.14: /* Beispiele */

2022-12-29T15:05:30Z

Beispiele

134.3.86.14: /* Beispiele */

2022-12-29T15:04:39Z

Beispiele

134.3.86.14: /* Beispiele */

2022-12-29T14:58:52Z

Beispiele

134.3.86.14: Die Seite wurde neu angelegt: „== Links == Swift - Snippets == Beispiele == import Foundation class CountdownTimer { var counter = 300 // Startwert f…“

2022-12-29T14:49:01Z

Die Seite wurde neu angelegt: „== Links == Swift - Snippets == Beispiele == <syntaxhighlight lang="swift"> import Foundation class CountdownTimer { var counter = 300 // Startwert f…“

Neue Seite

== Links ==
[[Swift - Snippets]]
== Beispiele ==
<syntaxhighlight lang="swift">
import Foundation

class CountdownTimer {
var counter = 300 // Startwert für den Zähler (300 Sekunden entspricht 5 Minuten)
var timer: Timer? // Der Timer selbst

func start() {
// Erstelle einen Timer, der jede Sekunde ausgelöst wird
timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(updateCounter), userInfo: nil, repeats: true)
}

@objc func updateCounter() {
counter -= 1 // Verringere den Zähler um 1
if counter == 0 {
timer?.invalidate() // Stoppe den Timer, wenn der Zähler 0 erreicht hat
}
}
}

let countdownTimer = CountdownTimer()
countdownTimer.start()

</syntaxhighlight>

@@ Zeile 54: / Zeile 54: @@
 There are a few issues here:
-    Every time onTimerFires is called, it is decrementing timeHours (which does not appear to be set or used anywhere) and then calls timeFunc, which just grabs values from the picker (which are not changing anywhere) to build the string.
+Every time onTimerFires is called, it is decrementing timeHours (which does not appear to be set or used anywhere) and then calls timeFunc, which just grabs values from the picker (which are not changing anywhere) to build the string.
-    This pattern of decrementing a counter in a timer makes a big assumption, namely that the timer is invoked exactly at the right time and that it will not ever miss a timer call. That is not a prudent assumption, unfortunately.
+This pattern of decrementing a counter in a timer makes a big assumption, namely that the timer is invoked exactly at the right time and that it will not ever miss a timer call. That is not a prudent assumption, unfortunately.
-    I would advise against the Selector based timer, as that introduces a strong reference cycle with the target. The block-based rendition with weak references is easier to avoid these sorts of cycles.
+I would advise against the Selector based timer, as that introduces a strong reference cycle with the target. The block-based rendition with weak references is easier to avoid these sorts of cycles.
 I would suggest a different pattern, namely that you save the time to which you are counting down:

@@ Zeile 1: / Zeile 1: @@
 == Links ==
   [[Swift - Snippets]]
 == Beispiele ==
 === Beispiel 1 ===

@@ Zeile 48: / Zeile 48: @@
 let countdownTimer = CountdownTimer()
+</syntaxhighlight>
 === Timer mit Startzeitpunkt ===

@@ Zeile 2: / Zeile 2: @@
   [[Swift - Snippets]]
 == Beispiele ==
+=== Beispiel 1 ===
 <syntaxhighlight lang="swift">
 import Foundation
@@ Zeile 26: / Zeile 26: @@
 </syntaxhighlight>
+=== Beispiel 2 ===
 <syntaxhighlight lang="swift">
 import Foundation