SwiftUI下截图不支持blur

Question

您好，在这篇文章中提到的截图方法非常有效，能够解决很多SwiftUI下大部份场景的截图需求，但在最近使用过程中发现其对blur这类效果却无法支持，不知道有没有什么办法能够实现？

Answer 1

如果没有其它特殊需求，就用 SwiftUI 原生的 ImageRenderer 即可：

struct BlurDemoView: View {
    var body: some View {
        VStack {
            Text("This is some text.")
                .padding()
            Text("This is some blurry text.")
                .blur(radius: 2.0)
        }
    }
}

struct ContentView: View {
    
    @State var image: UIImage?
    let content = BlurDemoView()
    
    var body: some View {
        NavigationStack {
            VStack(spacing: 32) {
                content
                
                if let image {
                    Image(uiImage: image)
                }
                
                Button("截图") {
                    
                    let renderer = ImageRenderer(content: content)
                    renderer.scale = 1.0
                    
                    if let cgImage = renderer.cgImage {
                        image = UIImage(cgImage: cgImage)
                    }
                }
                .padding(.top)
            }
        }
    }
}

如果有其它需求可以试试这个，但可能在某些情况下会有问题：

extension View {
    func snapshotNew(scale: CGFloat) -> UIImage {

        let controller = UIHostingController(rootView: self)
        let view = controller.view!
    
        let format = UIGraphicsImageRendererFormat()
        format.scale = scale
        // 可以开启或关闭背景透明
        //format.opaque = true
            
        var targetSize = controller.view.intrinsicContentSize
        let topEdgeInset = UIApplication.shared.windows.first { $0.isKeyWindow }!.safeAreaInsets.top
        view.bounds = CGRect(origin: .init(x: 0, y: topEdgeInset / 2), size: targetSize)
        view.backgroundColor = .clear
            
        // 将 SwiftUI 视图对应的 UIView 加入渲染并设为可见
        //let window = UIWindow(frame: view.bounds)
        //window.addSubview(controller.view)
        //window.makeKeyAndVisible()
            
        let renderer = UIGraphicsImageRenderer(bounds: view.bounds, format: format)
        
        return renderer.image { rendererContext in
            view.drawHierarchy(in: view.bounds, afterScreenUpdates: true)
        }
    }
}