Swift Document Picker，无法访问文件

Question

我正在编写一个项目，其中涉及选择一个文件并获取文件的内容。但是，我认为它没有到达文件的正确 url。

这是调用文档选择器的函数。它由一个按钮激活。

@IBAction func selectFile(_ sender: Any) {
        let documentPicker = UIDocumentPickerViewController(documentTypes: [kUTTypePlainText as String], in: .import)
        documentPicker.delegate = self
        documentPicker.allowsMultipleSelection = false
        present(documentPicker, animated: true, completion: nil)
}

这是对 UIDocumentPickerViewController 的扩展

extension ViewController: UIDocumentPickerDelegate {
    func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
        print(urls)
        do {
            let fileContent = try String(contentsOf: urls[0], encoding: .utf8)
            print(fileContent)
        } catch {
            return
        }
    }
}

在控制台输出中， fileContent没有被打印出来，相反，这是它打印出来的。

Failed to associate thumbnails for picked URL
file:///Users/<user>/Library/Developer/CoreSimulator/Devices/480A2D02-810F-435E-BF44-4B2F6FC614A9/data/Containers/Data/Application/BAA825D0-C4D8-4B33-AFB3-3737ADCA0B29/Documents/test2.txt with the Inbox copy 
file:///Users/<user>/Library/Developer/CoreSimulator/Devices/480A2D02-810F-435E-BF44-4B2F6FC614A9/data/Containers/Data/Application/BAA825D0-C4D8-4B33-AFB3-3737ADCA0B29/tmp/<project>-Inbox/test2.txt: 
Error Domain=QLThumbnailErrorDomain Code=102 "(null)" 
UserInfo={NSUnderlyingError=0x600003348060 
{Error Domain=GSLibraryErrorDomain Code=3 "Generation not found" UserInfo={NSDescription=Generation not found}}}

网上关于这个的资源不多，有人可以帮忙看看我在这里做错了什么吗？

Answer 1

实际上我对 UIDocumentPickerViewController 初始化程序做了一个小改动。添加下面的更新代码。

@IBAction func selectFile(_ sender: Any) {
    let documentPicker = UIDocumentPickerViewController(documentTypes: ["public.text"], in: .import)
    documentPicker.delegate = self
    documentPicker.allowsMultipleSelection = false
    present(documentPicker, animated: true, completion: nil) }

其余代码相同，仅替换了 ["public.text"] 而不是 [kUTTypePlainText as String]。

也许它可以解决您的问题。请让我知道反馈。
信用转至 adrian检查此链接 using-uidocumentpickerviewcontroller-to-import-text-in-swift