苹果原生NSURLSession的上传和下载
关于NSURLSession的上传和下载
在iOS7.0后,苹果公司新推出了一个NSURLSession来代替NSURLConnection。NSURLConnection默认是在 主线程执行的。而NSURLSession是在其他线程上执行的。本篇主要实现了下载和上传,比起NSURLConnection更加简单。线程控制掌握 更加清晰。
#pragma mark -下载
- (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]; }
#pragma mark -上传
- (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]; }
郑重声明:本站内容如果来自互联网及其他传播媒体,其版权均属原媒体及文章作者所有。转载目的在于传递更多信息及用于网络分享,并不代表本站赞同其观点和对其真实性负责,也不构成任何其他建议。