带有透明窗口的 SwiftUI 渲染错误

Question

在 macOS 应用程序中，我设置了

NSWindow.backgroundColor = .clear

。
当 SwiftUI 视图重新渲染时，它们之前渲染的版本通常会卡在后台。

这是一个错误，还是我做错了什么？
你知道解决方法吗？

环境：
macOS 12.5.1
Xcode 14.0

提前谢谢您。

import SwiftUI

@main
struct MacosPlaygroundApp: App {
    var body: some Scene {
        WindowGroup("Playground") {
            ContentView()
                .frame(width: 120, height: 300, alignment: .center)
        }
    }
}

struct ContentView: View {
    private let items: [Item] = [
        Item(id: "first", name: "First", sfSymbol: "house"),
        Item(id: "second", name: "Second", sfSymbol: "sun.max"),
        Item(id: "third", name: "Third", sfSymbol: "cloud"),
        Item(id: "fourth", name: "Fourth", sfSymbol: "trash"),
        Item(id: "fifth", name: "Fifth", sfSymbol: "scribble"),
    ]

    var body: some View {
        ScrollView {
            LazyVGrid(columns: [gridItem], alignment: .center, spacing: 10) {
                ForEach(items, id: \.id) { item in
                    itemView(item: item)
                }
            }
        }
        .onReceive(NotificationCenter.default.publisher(for: NSApplication.didBecomeActiveNotification)) { _ in
            if let mainWindow = NSApplication.shared.windows.first(where: { $0.title == "Playground" }) {
                mainWindow.backgroundColor = .clear
            }
        }
    }

    @ViewBuilder
    private func itemView(item: Item) -> some View {
        VStack(alignment: .center, spacing: 10) {
            Image(systemName: item.sfSymbol)
            Text(item.name)
        }
        .padding()
        .background(.pink.opacity(0.5))
        .cornerRadius(10)
    }

    private var gridItem: GridItem {
        GridItem(
            .adaptive(minimum: 100, maximum: 100),
            spacing: 10,
            alignment: .top
        )
    }

    private struct Item {
        let id: String
        let name: String
        let sfSymbol: String
    }
}

Answer 1

我找到了解决方法：

.backgroundColor = .white.withAlphaComponent(0.000001)

，而不是

.clear

。

窗口仍然显示透明（足够），并且我看不到渲染错误发生。

Answer 2

NSWindow.hasShadow = false

这应该有效。