I try to define the maximum windowsize in a MacOS SwiftUI App like this:

struct ContentView: View {
  @State var width = 400.0
  
  var body: some View {    
    VStack{
      GeometryReader { geometry in
        VStack {
          Text("Suggested Width : \(width)")
          Text("Width           : \(      geometry.size.width)")
          Text("Height          : \(      geometry.size.height)")
          Button("Set width to 200"){
            width = 200.0
          }
        }
        .padding()        
      }
      .frame(maxWidth: width)
    }    
    .background(Color.green)
  }
}

The .frame(maxWidth: width) only affects the "inner" green VStack.
The (MacOS)Window can be dragged bigger than the maxWidth.

How can I define the maximum Width for the (MacOS)Window?

CodePudding user response：

You can use .windowResizability in the App struct on the WindowGroup Scene.
If you set it to .contentSize it derives min and/or max values of the window size from the view sizes inside the window.

        WindowGroup {
            ContentView()
                .frame(minWidth: 100, maxWidth: 400, minHeight: 100, maxHeight: 400)
        }
        .defaultSize(width: 400, height: 400)
        .windowResizability(.contentSize) // here: this takes min and max sizes from the child view.