Question

我有一系列枚举，例如：

func downloadTask()  {
    // Create destination URL
    let documentsUrl:URL =  FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first as URL!
    let destinationFileUrl = documentsUrl.appendingPathComponent("downloadedFile.jpg")
    //Create URL to the source file you want to download
    let fileURL = URL(string: "http://placehold.it/120x120&text=image1")
    let sessionConfig = URLSessionConfiguration.default
    let session = URLSession(configuration: sessionConfig)
    let request = URLRequest(url:fileURL!)

    let task = session.downloadTask(with: request) { (tempLocalUrl, response, error) in
        if let tempLocalUrl = tempLocalUrl, error == nil {
            // Success
            if let statusCode = (response as? HTTPURLResponse)?.statusCode {
                print("Successfully downloaded. Status code: \(statusCode)")
            }

            do {
                try FileManager.default.copyItem(at: tempLocalUrl, to: destinationFileUrl)
            } catch (let writeError) {
                print("Error creating a file \(destinationFileUrl) : \(writeError)")
            }

        } else {
            print("Error took place while downloading a file. Error description: %@", error?.localizedDescription ?? "");
        }
    }
    task.resume()

}

迭代之后，我想要这样的东西：

let arr: [Any] = [Components.self, Periphery.self]

可能我需要一些可以返回特定类型的函数。我写的时候

“element.something”

，正是在这一刻我需要知道这种元素的类型。我怎样才能做到这一点？

Answer 1

我不确定你想要的但是这个有效：

Collection "@schematics/angular" cannot be resolved.
Error: Collection "@schematics/angular" cannot be resolved.

遍历任何类型的数组

1 个答案: