Question

好的，所以我有点疯狂，试图了解我的代码问题在哪里。我试图让单独的类进行通信，这样我就可以在文件下载过程中处理UI元素。

我选择的协议解决方案似乎完全符合我的需求：

协议：

protocol DownloadResponder : class {
    func downloadFinished()
}

下载课程： （为了问题我只显示download_zip func和didFinishDownloadingToURL代表）

import UIKit
import Foundation

typealias CompleteHandlerBlock = () -> ()

class fileDownloader: NSObject, NSURLSessionDelegate, NSURLSessionDownloadDelegate {

    //responder
    var responder : DownloadResponder?

    init(responder : DownloadResponder) {
        self.responder = responder
    }

    var session: NSURLSession!
    var handlerQueue: [String : CompleteHandlerBlock]!

//    class var sharedInstance: fileDownloader {
//        struct Static {
//            static var instance : fileDownloader?
//            static var token : dispatch_once_t = 0
//        }
//        
//        dispatch_once(&Static.token) {
//            Static.instance = fileDownloader()
//            Static.instance!.handlerQueue = [String : CompleteHandlerBlock]()
//        }
//        
//        return Static.instance!
//    }

    func download_zip(sURL: String, destination:String, name:String, fileis:Int) {

        var session:NSURLSessionTask!
        var sessionConfiguration:NSURLSessionConfiguration = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier("com.visi")
        sessionConfiguration.HTTPMaximumConnectionsPerHost = 5

        self.session = NSURLSession(configuration: sessionConfiguration, delegate: self, delegateQueue: nil)
        var url = NSURLRequest(URL: NSURL(string: sURL)!)
        var downloadTask:NSURLSessionDownloadTask = self.session.downloadTaskWithRequest(url)

        downloadTask.resume()
    }

    func URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didFinishDownloadingToURL location: NSURL) {
        println("session \(session) has finished the download task \(downloadTask) of URL \(location).")

        responder?.downloadFinished()
    }

我的FileInfo ViewController中的downloadFinished func ：

func downloadFinished() {
        downloadLbl.text = "Downloaded"
        println("DOWNLOAD OVER")
    }

最后，我的 FileInfo ViewController 中的函数：

func downloadFile(sender:UIButton!)
    {
     // some code...   

     fileDownloader().download_zip(datastring, destination: path, name: naming, fileis: self.fileId)
    }

我的视图控制器中的此函数调用fileDownloader().download_zip(datastring, destination: path, name: naming, fileis: self.fileId)会在添加协议之前触发我没有的错误。它说：Missing argument for parameter 'responder' in call。我想不出任何解决方案，所以如果有人知道它是什么请帮助！

Answer 1

在init fileDownloader responder: DownloadResponder方法中，当您在fileDownloader方法中初始化downloadFile时，您需要一个参数fileDownloader().download_zip(...

所以而不是：

fileDownloader(DownloadResponderImplementation()).download_zip(...

执行：

class DownloadResponderImplementation: DownloadResponder {
   func downloadFinished() {
      //Do something here
   }
}

这假设您还实现了DownloadResponder协议，例如：

dashboardPage(
                dashboardHeader(
                        title = "Example of a long title that needs more space",
                        titleWidth = 450
                ),
                dashboardSidebar( sidebarMenu(
                        menuItem("Dashboard", tabName = "dashboard", icon = icon("dashboard")),
                        menuItem("Widgets", icon = icon("th"), tabName = "widgets",
                                 badgeLabel = "new", badgeColor = "green")
                )),
                dashboardBody(
                        # Also add some custom CSS to make the title background area the same
                        # color as the rest of the header.
                        tags$head(tags$style(HTML('
        /* logo */
        .skin-blue .main-header .logo {
                              background-color: #f4b943;
                              }

        /* logo when hovered */
        .skin-blue .main-header .logo:hover {
                              background-color: #f4b943;
                              }

        /* navbar (rest of the header) */
        .skin-blue .main-header .navbar {
                              background-color: #f4b943;
                              }        

        /* main sidebar */
        .skin-blue .main-sidebar {
                              background-color: #f4b943;
                              }

        /* active selected tab in the sidebarmenu */
        .skin-blue .main-sidebar .sidebar .sidebar-menu .active a{
                              background-color: #ff0000;
                              }

        /* other links in the sidebarmenu */
        .skin-blue .main-sidebar .sidebar .sidebar-menu a{
                              background-color: #00ff00;
                              color: #000000;
                              }

        /* other links in the sidebarmenu when hovered */
         .skin-blue .main-sidebar .sidebar .sidebar-menu a:hover{
                              background-color: #ff69b4;
                              }
        /* toggle button when hovered  */                    
         .skin-blue .main-header .navbar .sidebar-toggle:hover{
                              background-color: #ff69b4;
                              }
                              ')))
                )


)

在调用swift中缺少参数'responder'的参数

1 个答案: