Swift - 如何在应用程序中运行 while 循环？

Question

I am trying to build a metronome app, where when activated the app flashes a light and plays a sound in given intervals. However, I don't know where to put a while loop, as putting it inside the viewcontroller prompts an "expected declaration" error. The idea is just for something like:

while metronome_is_on = true {
    //code that plays sound/flashes light with given delayed intervals
}

So, where can I run this loop in the app? Or is there a better practice for this?

Answer 1

As I understand, you probably are new to Swift, so here it goes...

All of your code setup, goes inside the ViewController's viewDidLoad . viewDidLoad is called the moment a ViewController is loaded into memory.

To play a sound, check here; How to play a sound using Swift?

To run a block of code on certain intervals, check here; https://www.hackingwithswift.com/articles/117/the-ultimate-guide-to-timer

As far your while-loop is concerned, have in mind that to check for equality you need == . = is used for value assignment.