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];



}

下载

 

#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];



}

上传