SwiftUI Repaint View Components on Device Rotation

Question

How to detect device rotation in SwiftUI and re-draw view components?

I have a @State variable initialized to the value of UIScreen.main.bounds.width when the first appears. But this value doesn't change when the device orientation changes. I need to redraw all components when the user changes the device orientation.

Answer 1

Here‘s an idiomatic SwiftUI implementation based on a notification publisher:

struct ContentView: View {          @State var orientation = UIDevice.current.orientation      let orientationChanged = NotificationCenter.default.publisher(for: UIDevice.orientationDidChangeNotification)         .makeConnectable()         .autoconnect()      var body: some View {         Group {             if orientation.isLandscape {                 Text("LANDSCAPE")             } else {                 Text("PORTRAIT")             }         }.onReceive(orientationChanged) { _ in             self.orientation = UIDevice.current.orientation         }     } } 

The output of the publisher (not used above, therefor _ as the block parameter) also contains the key "UIDeviceOrientationRotateAnimatedUserInfoKey" in its userInfo property if you need to know if the rotation should be animated.