SwiftUI 预览更新因存档错误而失败

Question

我目前正在学习iOS小部件，当我尝试预览我的小部件时遇到了这个奇怪的错误。以下是诊断的内容：

== PREVIEW UPDATE ERROR:

    PotentialCrashError: Update failed
    
    ZohoMailWidgetTest may have crashed. Check ~/Library/Logs/DiagnosticReports for any crash logs from your application.
    
    ==================================
    
    |  RemoteHumanReadableError
    |  
    |  ArchivingError: failedToEncode(types: [SwiftUI.(unknown context at $107d0ac9c).ListRepresentable<SwiftUI.CollectionViewListDataSource<Swift.Never>, SwiftUI.SelectionManagerBox<Swift.Never>>, SwiftUI.(unknown context at $107d0ac9c).ListRepresentable<SwiftUI.CollectionViewListDataSource<Swift.Never>, SwiftUI.SelectionManagerBox<Swift.Never>>])

我的代码的相关主体如下所示：

struct MailWidgetTestWidgetEntryView : View {
    var entry: Provider.Entry

    var body: some View {
        HStack {
            VStack {
                VStack {
                    Image(systemName: "envelope")
                    Text("494")
                }
                
                Image(systemName: "pencil.circle.fill")
                    .frame(maxHeight: .infinity, alignment: .bottom)
            }
            
            List {
                MailWidgetListCellView()
                MailWidgetListCellView()
                MailWidgetListCellView()
            }
        }
    }
}

struct MailWidgetListCellView: View {
    
    var body: some View {
        HStack {
            VStack {
                HStack {
                    Text("Team Spark")
                        .font(.subheadline)
                        .frame(maxWidth: .infinity, alignment: .leading)
                    Text("12:15 PM")
                        .font(.caption)
                    
                }
                
                Text("Use Spark to reclaim your focus")
                    .font(.subheadline)
                    .frame(maxWidth: .infinity, alignment: .leading)
            }
            
            Image(systemName: "checkmark.circle.fill")
                .font(.title)
                .frame(maxHeight: .infinity)
        }
    }
}

当我将

List

更改为

VStack

时，不会弹出此错误，如下所示：

struct MailWidgetTestWidgetEntryView : View {
    var entry: Provider.Entry

    var body: some View {
        HStack {
            VStack {
                VStack {
                    Image(systemName: "envelope")
                    Text("494")
                }
                
                Image(systemName: "pencil.circle.fill")
                    .frame(maxHeight: .infinity, alignment: .bottom)
            }
            
            VStack { //no errors now
                MailWidgetListCellView()
                MailWidgetListCellView()
                MailWidgetListCellView()
            }
        }
    }
}

我在其他地方找不到解决此问题的方法。有谁知道我该如何解决这个问题？

Answer 1

您不能在小部件中使用任何可滚动元素，因为它们不支持滚动。 WWDC 视频中提到了此行为。