swift iOS：在app documents文件夹中创建UIDocument

Question

我正在寻找一种方法如何做到这一点。我说选项如何使用alredy创建的文件，但UIDocument不能只从URL初始化。

所以，这是我的代码，它不起作用：

        weak var weakSelf = self
        let toFolder = presenter.interactor.url.path
        let name = "Untitled"
        var toPath = toFolder + "/" + name
        var count = 1
        while FileManager.default.fileExists(atPath: toPath) {
            toPath = toFolder + "/" + name + " (\(count))"
            count += 1
        }
        let url = (toPath + ".UTI").url!
        print(url.absoluteString)
        let document = Document(fileURL: url)
        document.save(to: url, for: UIDocument.SaveOperation.forCreating, completionHandler: { (success) in
            if success {
                vc.document = document
                vc.title = url.lastPathComponent
                let nvc = UINavigationController(rootViewController: vc)
                weakSelf?.userInterface.present(nvc, animated: true, completion: nil)
            } else {
                Alert.showError(body: "Could not create document".localized)
            }
        })

网址是：

/var/Mobile/containers/data/application/67C2A474-A054-4DF E-8587-B453A8B44554/documents/untitled.u TI

我崩溃了字符串：“let document = Document（fileURL：url）”

***由于未捕获的异常'NSInvalidArgumentException'而终止应用程序，原因：'必须将有效的文件URL传递给 - [UIDocument initWithFileURL：]'

班级文件：

enum DocumentError: Error {
case saveError
case loadError
}

class Document: UIDocument {

var text: String?

var encodingUsed: String.Encoding?

override func contents(forType typeName: String) throws -> Any {

    guard let data = text?.data(using: .utf8) else {
        throw DocumentError.saveError
    }

    return data
}

override func load(fromContents contents: Any, ofType typeName: String?) throws {

    guard let data = contents as? Data else {
        throw DocumentError.loadError
    }

    guard let utf8 = String(data: data, encoding: .utf8) else {
        throw DocumentError.loadError
    }

    self.text = utf8

}

}

var url: URL? {
    if self != "" && !isEmpty {
        return URL(string: self)
    } else {
        return nil
    }
}

Answer 1

你的扩展应该返回：URL(fileURLWithPath: self)而不是URL(string: self)，因为这是本地文件。

Answer 2

您创建路径和URL的代码需要大量工作。但最后你需要使用URL(fileURLWithPath:)创建一个文件URL并将其传递给你的Document。

let toFolder = presenter.interactor.url
let name = "Untitled"
var toPath = toFolder.appendingPathComponent(name)
var count = 1
while FileManager.default.fileExists(atPath: toPath.path) {
    toPath = toFolder.appendingPathComponent(name + " (\(count))")
    count += 1
}
let url = toPath.appendingPathExtension("UTI")
print(url.path)
let document = Document(fileURL: url)