对于Swift 4 - 5将此添加到 applicationDidEnterBackground(_ application: UIApplication)
var appGroupIdentifier = "XXXXXXX"
let fromURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: appGroupIdentifier)
let docURL = try! FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
let toURL = docURL.appendingPathComponent(appGroupIdentifier)
try? FileManager.default.removeItem(at: toURL)
try? FileManager.default.copyItem(at: fromURL, to: toURL)
然后使用 xcode 下载应用程序容器。