NSURL＆＃39？;没有会员＆＃39;路径＆＃39;

Question

此代码曾用于Swift和Xcode Beta：

@IBAction func chooseTargerDir(sender: AnyObject) {

    let myFiledialog:NSOpenPanel = NSOpenPanel()
    myFiledialog.allowsMultipleSelection = false
    myFiledialog.canChooseDirectories = true
    myFiledialog.runModal()

    var chosenfile = myFiledialog.URL 
    arg2.stringValue = chosenfile.path

现在在Xcode 6.1中，我收到错误：

'NSURL?' does not have a member 'path'