iOS开发——网络编程Swift篇&（七）NSURLSession详解

  1     // MARK: - /* 使用NSURLSessionDataTask加载数据 */
  2     func sessionLoadData()
  3     {
  4         //创建NSURL对象
  5         var url:NSURL! = NSURL(string: "http://m.weather.com.cn/data/101010100.html")
  6         
  7         //创建请求对象
  8         var request : NSURLRequest = NSURLRequest(URL: url)
  9         
 10         let session = NSURLSession.sharedSession()
 11         
 12         
 13         var dataTask = session.dataTaskWithRequest(request, completionHandler: { (var data:NSData?, var response:NSURLResponse?, var error:NSError?) -> Void in
 14             
 15             //返回错误信息情况
 16             if (error != nil)
 17             {
 18                 println(error?.code)
 19                 println(error?.description)
 20             }else
 21             {
 22                 var jsonString = NSString(data: data!, encoding: NSUTF8StringEncoding)
 23                 println(jsonString)
 24             }
 25         }) as NSURLSessionTask
 26         
 27         //使用resume方法启动任务
 28         dataTask.resume()
 29     }
 30     
 31     
 32     
 33     // MARK: - /* 使用NSURLSessionDataTask下载文件  ---- 简单下载，不需要知道下载进度 */
 34     func sessionSimpleDownload()
 35     {
 36         //下载地址
 37         var url = NSURL(string: "http://www.iphonetrain.com/shop/data/ios/201404/source/2809080296130100.jpg")
 38         //请求
 39         var request = NSURLRequest(URL: url!)
 40         //连接
 41         var session = NSURLSession.sharedSession()
 42         //下载任务
 43         var downloadTask = session.downloadTaskWithRequest(request, completionHandler: { (var location:NSURL?,var response:NSURLResponse?, var error:NSError?) -> Void in
 44 
 45             // 输出下载文件原来的存放目录
 46             println("location: \(location)")
 47 
 48             //location位置转换
 49             var locationPath = location?.path
 50 
 51             //拷贝到我们自己目录中
 52             let documents:String = NSHomeDirectory() + "/Documents/1.png"
 53 
 54             // 创建文件管理器
 55             var fileManager :NSFileManager = NSFileManager.defaultManager()
 56             fileManager.moveItemAtPath(locationPath!, toPath: documents, error: nil)
 57             println("location: \(documents)")
 58         })
 59         
 60         //使用resume方法启动任务
 61         downloadTask.resume()
 62     }
 63     
 64  
 65     // MARK: - /* 使用NSURLSessionDataTask下载文件  ---- 获取进度 */
 66     //创建一个下载模式--单利实现
 67     func currentSession()->NSURLSession{
 68         
 69         var predicate:dispatch_once_t = 0
 70         var currentSession:NSURLSession? = nil
 71         
 72         dispatch_once(&predicate,{
 73             
 74             var config = NSURLSessionConfiguration.defaultSessionConfiguration()
 75             
 76             currentSession = NSURLSession(configuration: config, delegate: self, delegateQueue: nil)
 77             }
 78         )
 79         return currentSession!
 80     }
 81     
 82     func sessionSeniorDownload()
 83     {
 84         //下载地址
 85         var url = NSURL(string: "http://www.iphonetrain.com/shop/data/ios/201404/source/2809080296130100.jpg")
 86         //请求
 87         var request = NSURLRequest(URL: url!)
 88         
 89         //连接
 90         var session = currentSession() as NSURLSession
 91         
 92         //下载任务
 93         var downloadTask = session.downloadTaskWithRequest(request)
 94         
 95         //使用resume方法启动任务
 96         downloadTask.resume()
 97     }
 98 
 99     
100      // MARK: - NSURLSessionDownloadDelegate
101     func URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didFinishDownloadingToURL location: NSURL)
102     {
103         //下载结束
104         println("下载结束")
105         
106     }
107     func URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64)
108     {
109         //获取进度
110          var written:CGFloat = (CGFloat)(bytesWritten)
111          var total:CGFloat = (CGFloat)(totalBytesExpectedToWrite)
112         
113         var pro:CGFloat = written / total
114         println("下按进度：\(pro)")
115     }
116     func URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didResumeAtOffset fileOffset: Int64, expectedTotalBytes: Int64)
117     {
118         //下载偏移，主要用于暂停续传
119     }
120     
121     
122     
123     
124     // MARK: -  /* 使用NSURLSessionDataTask上传文件 */
125     func sessionUpload()
126     {
127         //上传的位置地址
128         var url = NSURL(string: "http://www.iphonetrain.com/shop/data/")
129         
130         //请求
131         var request = NSURLRequest(URL: url!)
132         
133         //连接
134         var session = NSURLSession.sharedSession()
135         
136         //上传数据流
137         let documents:String = NSHomeDirectory() + "/Documents/1.png"
138         var imgData = NSData(contentsOfFile: documents)
139         
140         var uploadTask = session.uploadTaskWithRequest(request, fromData: imgData, completionHandler: { (var data:NSData?, var response:NSURLResponse?, var error:NSError?) -> Void in
141             
142             //上传完毕之后判断
143             println("上传完毕")
144         })
145         
146         //使用resume方法启动任务
147         uploadTask.resume()
148     }