p1-c01-🕰-plus-one-second

C01 - 🕰 Plus One Second

Timer with a button to plus one second per click.

Notes

The Timer Logic

To refresh our interface every 0.1 second, we should use a timer and declare how should the interface works.

The @State recreates the interface every time the date is updated.

@State var timeCount: Double = 0.0

var timer: Timer {
    Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) {timer in
        self.timeCount += 0.1
    }
}

Time Formating

The timer should run like 0.1s, so we must create a function to format the time.

func timeString(time: Double) -> String {
    return String(format: "%.1f", time)
}

Using the timer

Use onAppear to initialize the timer.

Text(timeString(time: timeCount))
  .onAppear(perform: {
      let _ = self.timer
  })

References

• How To Make a Simple Countdown Timer with SwiftUI