SwiftUI 在 preview 界面进行截图

方法一

直接在 #Preview 中呼叫。点击三下后即可完成截图。

import SwiftUI

struct PreviewScreenshotModifier: ViewModifier {
    let screenshotDirectoryURL = URL(filePath: "/Users/wonderhoi/")
    let tapCount = 3

    func body(content: Content) -> some View {
        content
            .onTapGesture(count: tapCount, perform: {
                let scene = UIApplication.shared.connectedScenes.first as? UIWindowScene
                let window = scene?.keyWindow ?? UIWindow(frame: .zero)
                let renderer = UIGraphicsImageRenderer(size: window.bounds.size)
                let image = renderer.image { context in
                    window.drawHierarchy(in: window.bounds, afterScreenUpdates: true)
                }
                let pngData = image.pngData()
                let screenshotURL = screenshotDirectoryURL.appending(path: "\(UUID())").appendingPathExtension(for: .png)
                try? image.pngData()?.write(to: screenshotURL)
             })
    }
}

extension View {
    func previewScreenshot() -> some View {
        modifier(PreviewScreenshotModifier())
    }
}

使用

#Preview {
	ContentView()
		.previewScreenshot()
}

方法二

通过按钮或者 onTap 等手势触发。

Button(action: {
    
    let screenshotDirectoryURL = URL(filePath: "/Users/wonderhoi/")
    let scene = UIApplication.shared.connectedScenes.first as? UIWindowScene
    let window = scene?.keyWindow ?? UIWindow(frame: .zero)
    let renderer = UIGraphicsImageRenderer(size: window.bounds.size)
    let image = renderer.image { context in
        window.drawHierarchy(in: window.bounds, afterScreenUpdates: true)
    }
    let pngData = image.pngData()
    let screenshotURL = screenshotDirectoryURL.appending(path: "\(UUID())").appendingPathExtension(for: .png)
    try? image.pngData()?.write(to: screenshotURL)
    
}, label: {
    Text("截屏")
})