swift - 使用 swift 在沙盒 Mac 应用程序中访问文件

Question

我正在为 OS X 10.9 使用 Swift 沙盒开发应用程序。

该应用需要访问 SQLite 数据库文件。我让用户使用 NSOpenPanel 选择/打开文件。然后我用 NSUserDefaults 保存文件路径以备后用。

我希望每次再次启动应用程序时自动打开此文件。我从 NSUserDefault 获取存储的路径，但是当我使用此路径打开文件时出现错误，提示我无权访问该文件。

(它在没有沙盒的情况下工作)

看来书签可以解决我的问题。

是否有关于如何将书签与 swift 一起用于 osx 应用程序的好教程？还有其他建议吗？

Answer 1

这是我的回答，我刚刚在 http://swiftrien.blogspot.com/2015/07/persisting-file-access-rights-between.html 的帮助下开始使用 Swift 3

import Foundation
import Cocoa

var bookmarks = [URL: Data]()

func bookmarkPath() -> String
{
    var url = app.applicationDocumentsDirectory
    url = url.appendingPathComponent("Bookmarks.dict")
    return url.path
}

func loadBookmarks()
{
    let path = bookmarkPath()
    bookmarks = NSKeyedUnarchiver.unarchiveObject(withFile: path) as! [URL: Data]
    for bookmark in bookmarks
    {
        restoreBookmark(bookmark)
    }
}

func saveBookmarks()
{
    let path = bookmarkPath()
    NSKeyedArchiver.archiveRootObject(bookmarks, toFile: path)
}

func storeBookmark(url: URL)
{
    do
    {
        let data = try url.bookmarkData(options: NSURL.BookmarkCreationOptions.withSecurityScope, includingResourceValuesForKeys: nil, relativeTo: nil)
        bookmarks[url] = data
    }
    catch
    {
        Swift.print ("Error storing bookmarks")
    }

}

func restoreBookmark(_ bookmark: (key: URL, value: Data))
{
    let restoredUrl: URL?
    var isStale = false

    Swift.print ("Restoring \(bookmark.key)")
    do
    {
        restoredUrl = try URL.init(resolvingBookmarkData: bookmark.value, options: NSURL.BookmarkResolutionOptions.withSecurityScope, relativeTo: nil, bookmarkDataIsStale: &isStale)
    }
    catch
    {
        Swift.print ("Error restoring bookmarks")
        restoredUrl = nil
    }

    if let url = restoredUrl
    {
        if isStale
        {
            Swift.print ("URL is stale")
        }
        else
        {
            if !url.startAccessingSecurityScopedResource()
            {
                Swift.print ("Couldn't access: \(url.path)")
            }
        }
    }

}

func allowFolder() -> URL?
{
    let openPanel = NSOpenPanel()
    openPanel.allowsMultipleSelection = false
    openPanel.canChooseDirectories = true
    openPanel.canCreateDirectories = true
    openPanel.canChooseFiles = false
    openPanel.begin
        { (result) -> Void in
            if result == NSFileHandlingPanelOKButton
            {
                let url = openPanel.url
                storeBookmark(url: url!)
            }
    }
    return openPanel.url
}

Swift 4(更新):

import Foundation
import Cocoa

var bookmarks = [URL: Data]()

func fileExists(_ url: URL) -> Bool
{
    var isDir = ObjCBool(false)
    let exists = FileManager.default.fileExists(atPath: url.path, isDirectory: &isDir)

    return exists
}

func bookmarkURL() -> URL
{
    let urls = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)
    let appSupportURL = urls[urls.count - 1]
    let url = appSupportURL.appendingPathComponent("Bookmarks.dict")
    return url
}

func loadBookmarks()
{

    let url = bookmarkURL()
    if fileExists(url)
    {
        do
        {
            let fileData = try Data(contentsOf: url)
            if let fileBookmarks = try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(fileData) as! [URL: Data]?
            {
                bookmarks = fileBookmarks
                for bookmark in bookmarks
                {
                    restoreBookmark(bookmark)
                }
            }
        }
        catch
        {
            print ("Couldn't load bookmarks")
        }

    }
}

func saveBookmarks()
{
    let url = bookmarkURL()
    do
    {
        let data = try NSKeyedArchiver.archivedData(withRootObject: bookmarks, requiringSecureCoding: false)
        try data.write(to: url)
    }
    catch
    {
        print("Couldn't save bookmarks")
    }
}    

func storeBookmark(url: URL)
{
    do
    {
        let data = try url.bookmarkData(options: NSURL.BookmarkCreationOptions.withSecurityScope, includingResourceValuesForKeys: nil, relativeTo: nil)
        bookmarks[url] = data
    }
    catch
    {
        Swift.print ("Error storing bookmarks")
    }

}

func restoreBookmark(_ bookmark: (key: URL, value: Data))
{
    let restoredUrl: URL?
    var isStale = false

    Swift.print ("Restoring \(bookmark.key)")
    do
    {
        restoredUrl = try URL.init(resolvingBookmarkData: bookmark.value, options: NSURL.BookmarkResolutionOptions.withSecurityScope, relativeTo: nil, bookmarkDataIsStale: &isStale)
    }
    catch
    {
        Swift.print ("Error restoring bookmarks")
        restoredUrl = nil
    }

    if let url = restoredUrl
    {
        if isStale
        {
            Swift.print ("URL is stale")
        }
        else
        {
            if !url.startAccessingSecurityScopedResource()
            {
                Swift.print ("Couldn't access: \(url.path)")
            }
        }
    }

}

func allowFolder() -> URL?
{
    let openPanel = NSOpenPanel()
    openPanel.allowsMultipleSelection = false
    openPanel.canChooseDirectories = true
    openPanel.canCreateDirectories = true
    openPanel.canChooseFiles = false
    openPanel.begin
        { (result) -> Void in
            if result == NSFileHandlingPanelOKButton
            {
                let url = openPanel.url
                storeBookmark(url: url!)
            }
    }
    return openPanel.url
}

要使用此代码，您必须首先调用 NSOpenPanel，以便用户可以选择要授予您访问权限的文件夹。 NSOpenPanel 必须存储为书签并保存到磁盘。

let url = allowFolder()
saveBookmarks()

当您重新启动应用程序时，您必须调用

loadBookmarks()

然后您的应用将具有与用户选择文件夹时相同的访问级别。希望这对某人有帮助。