swift - Xcode 12 和 SwiftUI：无法在此文件中预览 - 无法更新预览

Question

似乎预览停止在 Xcode 12 上运行！尝试预览 SwiftUI 文件模板并收到以下错误。任何想法如何解决这一问题？尝试清理构建文件夹，删除派生数据并重新启动 Xcode 无济于事！

在 Catalina 10.15.6 上。

RemoteHumanReadableError: Failed to update preview.

The preview process appears to have crashed.

Error encountered when sending 'prepare' message to agent.

==================================

|  RemoteHumanReadableError: The operation couldn’t be completed. (BSServiceConnectionErrorDomain error 3.)
|  
|  BSServiceConnectionErrorDomain (3):
|  ==BSErrorCodeDescription: OperationFailed

我试图预览的代码（来自 SwiftUI 新文件模板）：

import SwiftUI

struct SwiftUIView: View {
    var body: some View {
        Text("Hello, World!")
    }
}

struct SwiftUIView_Previews: PreviewProvider {
    static var previews: some View {
        SwiftUIView()
    }
}

标签： swiftswiftuixcode12

Answer 1

如果你SwiftUIView使用ObservableObjectas environmentObject，试试这个：

struct SwiftUIView_Previews: PreviewProvider {
    static var previews: some View {
        SwiftUIView().environmentObject(YourObservableObjectClass())
    }
}