Modifying state during view update

Using Swift
#1

Any explanation for this error? Thank you

Screen Shot 2020-06-08 at 12.10.18 PM
Screen Shot 2020-06-08 at 12.10.18 PM2496×448 156 KB

#2

You're inside one of View.body function. SwiftUI is gathering data to display your view. You shouldn't update data, especially @State during this time, it will cause unexpected result.

Instead, use one of event handlers like onAppear–Input and Events.

Function Calls in Swiftui
#3

Thanks for your quick response