Question

我正在编写一个应用程序，我可以从网上输入一个mp3文件的URL，当我点击下载时，该应用程序将在应用程序中下载它。有人能帮我吗？我是ios开发的新手。我正在努力学习Swift

Answer 1

Xcode 8•Swift 3

if let audioUrl = URL(string: "http://freetone.org/ring/stan/iPhone_5-Alarm.mp3") {

    // then lets create your document folder url
    let documentsDirectoryURL =  FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

    // lets create your destination file url
    let destinationUrl = documentsDirectoryURL.appendingPathComponent(audioUrl.lastPathComponent)
    print(destinationUrl)

    // to check if it exists before downloading it
    if FileManager.default.fileExists(atPath: destinationUrl.path) {
        print("The file already exists at path")

        // if the file doesn't exist
    } else {

        // you can use NSURLSession.sharedSession to download the data asynchronously
        URLSession.shared.downloadTask(with: audioUrl, completionHandler: { (location, response, error) -> Void in
            guard let location = location, error == nil else { return }
            do {
                // after downloading your file you need to move it to your destination url
                try FileManager.default.moveItem(at: location, to: destinationUrl)
                print("File moved to documents folder")
            } catch let error as NSError {
                print(error.localizedDescription)
            }
        }).resume()
    }
}

Xcode 7.2.1•Swift 2.1.1

//  First you need to create your audio url

    if let audioUrl = NSURL(string: "http://freetone.org/ring/stan/iPhone_5-Alarm.mp3") {

        // then lets create your document folder url
        let documentsDirectoryURL =  NSFileManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first!

        // lets create your destination file url
        let destinationUrl = documentsDirectoryURL.URLByAppendingPathComponent(audioUrl.lastPathComponent ?? "audio.mp3")
        print(destinationUrl)

        // to check if it exists before downloading it
        if NSFileManager().fileExistsAtPath(destinationUrl.path!) {
            print("The file already exists at path")

            // if the file doesn't exist
        } else {

            // you can use NSURLSession.sharedSession to download the data asynchronously
            NSURLSession.sharedSession().downloadTaskWithURL(audioUrl, completionHandler: { (location, response, error) -> Void in
                guard let location = location where error == nil else { return }
                do {
                    // after downloading your file you need to move it to your destination url
                    try NSFileManager().moveItemAtURL(location, toURL: destinationUrl)
                    print("File moved to documents folder")
                } catch let error as NSError {
                    print(error.localizedDescription)
                }
            }).resume()
        }
    }

Xcode：下载mp3文件

1 个答案: