Is there a method to blur a background in SwiftUI?

Question

I'm looking to blur a view's background but don't want to have to break out into UIKit to accomplish it (eg. a UIVisualEffectView) I'm digging through docs and got nowhere, seemingly there is no way to live-clip a background and apply effects to it. Am I wrong or looking into it the wrong way?

Answer 1

1. The Native SwiftUI way:

Just add .blur() modifier on anything you need to be blurry like:

Image("BG")
   .blur(radius: 20)

_{Note the top and bottom of the view}

Note that you can Group multiple views and blur them together.

---

2. The Visual Effect View:

You can bring the prefect UIVisualEffectView from the UIKit:

VisualEffectView(effect: UIBlurEffect(style: .dark))

With this tiny struct:

struct VisualEffectView: UIViewRepresentable {
    var effect: UIVisualEffect?
    func makeUIView(context: UIViewRepresentableContext<Self>) -> UIVisualEffectView { UIVisualEffectView() }
    func updateUIView(_ uiView: UIVisualEffectView, context: UIViewRepresentableContext<Self>) { uiView.effect = effect }
}

---

3. iOS 15: Materials

You can use iOS predefined materials with one line code:

.background(.ultraThinMaterial)

Answer 2

I haven't found a way to achieve that in SwiftUI yet, but you can use UIKit stuff via UIViewRepresentable protocol.

struct BlurView: UIViewRepresentable {

    let style: UIBlurEffect.Style

    func makeUIView(context: UIViewRepresentableContext<BlurView>) -> UIView {
        let view = UIView(frame: .zero)
        view.backgroundColor = .clear
        let blurEffect = UIBlurEffect(style: style)
        let blurView = UIVisualEffectView(effect: blurEffect)
        blurView.translatesAutoresizingMaskIntoConstraints = false
        view.insertSubview(blurView, at: 0)
        NSLayoutConstraint.activate([
            blurView.heightAnchor.constraint(equalTo: view.heightAnchor),
            blurView.widthAnchor.constraint(equalTo: view.widthAnchor),
        ])
        return view
    }

    func updateUIView(_ uiView: UIView,
                      context: UIViewRepresentableContext<BlurView>) {

    }

}

Demo:

struct ContentView: View {

    var body: some View {
        NavigationView {
            ZStack {
                List(1...100) { item in
                    Rectangle().foregroundColor(Color.pink)
                }
                .navigationBarTitle(Text("A List"))
                ZStack {
                    BlurView(style: .light)
                        .frame(width: 300, height: 300)
                    Text("Hey there, I'm on top of the blur")

                }
            }
        }
    }

}

I used ZStack to put views on top of it.

ZStack {
 // List
 ZStack {
    // Blurred View
    // Text
 }
}

And ends up looking like this: