swift - 第一次使用 Xcode 7 时，我收到了一个额外的参数错误调用，代码如下 -

Question

获取与下面的“items”常量相关的额外参数错误调用。这在 Xcode 7.0 之后有变化吗？

override func viewDidLoad() {
        super.viewDidLoad()
        let fm = NSFileManager.defaultManager()
        let path = NSBundle.mainBundle().resourcePath!
        let items = fm.contentsOfDirectoryAtPath(path, error: nil)

        for item in items as! [String] {
            if item.hasPrefix("nssl") {
                objects.append(item)
            }
        }

Answer 1

根据 Apple 的 contentsOfDirectoryAtPath:

In Swift, this method returns a nonoptional result and is marked with the throws keyword to indicate that it throws an error in cases of failure.

You call this method in a try expression and handle any errors in the catch clauses of a do statement, as described in Error Handling in The Swift Programming Language (Swift 2).

在 Swift 2.0 中新的/正确的方法是这样的:

        let fm = NSFileManager.defaultManager()
        let path = NSBundle.mainBundle().resourcePath!

        do {
            let items = try fm.contentsOfDirectoryAtPath(path)

            for item in items as! [String] {
                if item.hasPrefix("nssl") {
                    objects.append(item)
                }
            }
        }
        catch let error as NSError {
            error.description 
        }