- (IBAction)DownLoad{//1.URL
NSString *urlStr = @"http://she.21cn.com/emotions/mingren/a/2014/0309/15/26645767.shtml";NSURL *url = [NSURL URLWithString:urlStr];//2.NSURLRequest
NSURLRequest *request = [NSURLRequestrequestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicytimeoutInterval:5.0];//3.NSURLSession
NSURLSession *session = [NSURLSessionsharedSession];NSURLSessionDownloadTask *downLoad = [session downloadTaskWithRequest:request completionHandler:^(NSURL *location, NSURLResponse *response, NSError *error) {if (error) {NSLog(@"error = %@",error.localizedDescription);}else{// location是下载的临时文件目录
NSLog(@"%@", location);// 如果要保存文件,需要将文件保存至沙盒// 1. 根据URL获取到下载的文件名
NSString *fileName = [urlStr lastPathComponent];// 2. 生成沙盒的路径
NSArray *docs = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);NSString *path = [docs[0] stringByAppendingPathComponent:fileName];NSURL *toURL = [NSURL fileURLWithPath:path];// 3. 将文件从临时文件夹复制到沙盒,在iOS中所有的文件操作都是使用NSFileManager
[[NSFileManager defaultManager] copyItemAtURL:location toURL:toURL error:nil];// 4. 将图像设置到UIImageView
dispatch_async(dispatch_get_main_queue(), ^{UIImage *image = [[UIImage alloc] initWithContentsOfFile:path];_imageView.image = image;});}}];//4.因为任务默认是挂起状态，需要恢复任务（执行任务）
[downLoad resume];}

- (IBAction)upLoad{// 0. 判断imageView是否有内容if (_imageView.image == nil) {NSLog(@"image view is empty");return;}// 0. 上传之前在界面上添加指示符
UIActivityIndicatorView *indicator = [[UIActivityIndicatorViewalloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];// 设置位置???
CGSize size = _imageView.bounds.size;indicator.center = CGPointMake(size.width / 2.0, size.height / 2.0);[self.imageView addSubview:indicator];[indicator startAnimating];// 1. URL
NSString *urlStr = @"http://192.168.3.251/uploads/123.jpg";NSURL *url = [NSURL URLWithString:urlStr];// 2. Request -> PUT,request的默认操作是GET
NSMutableURLRequest *request = [NSMutableURLRequestrequestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicytimeoutInterval:5.0f];request.HTTPMethod = @"PUT";// *** 设置网络请求的身份验证! ***// 1> 授权字符串
NSString *authStr = @"admin:123456";// 2> BASE64的编码,避免数据在网络上以明文传输// iOS中,仅对NSData类型的数据提供了BASE64的编码支持
NSData *authData = [authStr dataUsingEncoding:NSUTF8StringEncoding];NSString *encodeStr = [authData base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithCarriageReturn];NSString *authValue = [NSString stringWithFormat:@"Basic %@", encodeStr];[request setValue:authValue forHTTPHeaderField:@"Authorization"];// 3. Session
NSURLSession *session = [NSURLSessionsharedSession];// 4. UploadTask
NSData *imageData = UIImageJPEGRepresentation(_imageView.image, 0.75);NSURLSessionUploadTask *upload = [session uploadTaskWithRequest:request fromData:imageData completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {// 上传完成后,data参数转换成string就是服务器返回的内容
NSString *str = [[NSStringalloc] initWithData:data encoding:NSUTF8StringEncoding];NSLog(@"OK -> %@", str);if (error != nil) {NSLog(@"ERROR -> %@", error.localizedDescription);} else {}[NSThreadsleepForTimeInterval:5.0f];dispatch_async(dispatch_get_main_queue(), ^{[indicator stopAnimating];[indicator removeFromSuperview];});}];[upload resume];}