SWIFT: NSURL 始终为 Nil 或不可用

Question

所以在我的 Swift 应用程序中，我有一个选择 folder/Drive 的函数 - 然后我想将 NSURL 用作字符串。但是-当我打印 NSURL 时，它显示为 "Optional(file:///(stuff goes here)" 但是当我将它设为 String 时，它显示为 Nil。我做错了什么吗？下面的代码

@IBAction func selectDrive(sender: AnyObject) {
    var openPanel = NSOpenPanel()
    openPanel.allowsMultipleSelection = false
    openPanel.canChooseDirectories = true
    openPanel.canCreateDirectories = true
    openPanel.canChooseFiles = false
    openPanel.beginWithCompletionHandler { (result) -> Void in
        if result == NSFileHandlingPanelOKButton {
            println(openPanel.URL)
            self.url = openPanel.URL!

            var loc = String(contentsOfURL: self.url)
            println("Location is at \(loc)")
            // var str = String(system("diskutil info \(loc) | grep UUID:"))

        }

    }
}

我还在顶部声明了以下内容

var url = NSURL()
@IBOutlet weak var driveLabel: NSTextField!

如有任何帮助，我们将不胜感激。昨晚我花了几个小时试图让控制台输出以字符串形式返回，试图将 NSURL 转换为字符串，试图删除整个应用程序...

Answer 1

NSOpenPanel returns 始终是 url 与 file:// 方案，您可以获得其 path 属性[ 的字符串表示形式=14=]

@IBAction func selectDrive(sender: AnyObject) {
    var openPanel = NSOpenPanel()
    openPanel.allowsMultipleSelection = false
    openPanel.canChooseDirectories = true
    openPanel.canCreateDirectories = true
    openPanel.canChooseFiles = false
    openPanel.beginWithCompletionHandler { (result) -> Void in
        if result == NSFileHandlingPanelOKButton {

            self.url = openPanel.URL!
            println("Location is at \(self.url.path!)")
        }
    }
}

SWIFT: NSURL 始终为 Nil 或不可用

SWIFT: NSURL Always either Nil or unusable

macos

nsurl

swift