NSURLSession

字数统计: 198阅读时长: 1 min

 2014/12/17   Share

var getImageTask:NSURLSessionDownloadTask =
        self.session!.downloadTaskWithURL(NSURL(string:imageUrlBasic), completionHandler: { (url:NSURL!, response:NSURLResponse!, error:NSError!) -> Void in
            // handle dwnloaded data
            var data = NSData(contentsOfURL:url!)
            var downloadedImage:UIImage = UIImage(data:data)
            dispatch_async(dispatch_get_main_queue()){
                // do stuff with image
                self.myImageView.image = downloadedImage
                println("downloadtask with closure")
                self.myLabel.text = "downloadtask with closure"
            }
        })

创建一个图片下载任务，NSURL是下载任务网址，completionHandler指定任务完成后的回调代码块，responce是一个闭包，任务完成后在主线程更新imageview

过程：

在 downloadtask 中

download task convenience methods. When a download successfully
completes, the NSURL will point to a file that must be read or
copied during the invocation of the completion routine. The file
will be removed automatically.
下载任务完成后，调用协议的

1	func URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didFinishDownloadingToURL location: NSURL)｛｝

方法

dataTaskWithRequest过程：

1.创建一个NSMutableURLRequest类

2.用NSMutableURLRequest作为参数创建一个任务，类为dataTaskWithURL

参考

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