iOS 14 Invalid frame dimension (negative or non-finite)

My App uses GeometryReader with some padding to setup a View frame dimension inside a NavigationView.

Since iOS 14 i get the following error message:

Invalid frame dimension (negative or non-finite)

Here is some example code to test:

import SwiftUI

struct ContentView: View {

    let padding:CGFloat = 16.0

    var body: some View {
        NavigationView {
            GeometryReader { p in
        Text("Hello, world!")
            .frame(width: p.size.width - padding)
            .padding()
            }
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

Removing NavigationView fix the problem, but I need the current width and height of the container View inside the NavigationView.

Any suggestion?

I think it might be a static analysis issue as .frame(width: p.size.width - padding) could result in a negative value. Try:

.frame(width: abs(p.size.width - padding))

When I tested with macOS 11.1, I found that GeometryReader could not return the actual size immediately at the beginning of the view init, the size obtained for the first time was incorrect, maybe need to do a dispatch async operation to avoid this warning

I ran into the same issue. I didn't get to the bottom of why being in a NavigationView causes this, but a workaround is to wrap the whole NavigationView in a GeometryReader and pass the GeometryProxy down the tree.

this helped me:

i added a Group { } around my first Element (which was a VStack with a .frame) in the body. The group has no ".frame" etc. worked on my MacOS app to get rid of this stupid issue.

or you can add something like

.frame(minWidth: 300, idealWidth: 400, maxWidth: 600, minHeight: 300, idealHeight: 400, maxHeight: 500, alignment: .top)

to your VStack (or whatever) to clearly say what dimensions you want.

edit strange this error will appear again, but not immediatly...