NSURLDownload委托问题

Question

class ImageFetcher {

    /* Initialize class variables and init function */


    func fetch(){

        var imageRequest = NSURLRequest(URL: self.source)
        var imageDownload = NSURLDownload(request: imageRequest, delegate: self)

        /* does path exist */
        let directoryPath = self.destination.stringByDeletingLastPathComponent
        let fileMgr = NSFileManager();
        fileMgr.createDirectoryAtPath(directoryPath, withIntermediateDirectories: true, attributes: nil, error: nil)

        imageDownload.setDestination(self.destination, allowOverwrite: true)
    }
}

我遇到的问题是台词

var imageDownload = NSURLDownload(request: imageRequest, delegate: self)

它抱怨说，“无法找到接受类型参数列表的'NSURLDownload‘初始化器’(请求: NSURLRequest，委托: ImageFetcher)‘我认为它与”自我“有关。我试图把它转换为一个NSURLDownloadDelegate，但它抱怨说它做不到。”

有什么建议吗？

Answer 1

请把你的课做得很好，如：

class ImageFetcher : NSObject, NSURLDownloadDelegate {

然后用以下方式调用init行：

var imageDownload = NSURLDownload(request: imageRequest, delegate: self)