ViewController.h
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController<NSURLSessionDelegate, NSURLSessionDownloadDelegate>
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@property (weak, nonatomic) IBOutlet UIProgressView *progressView;
@end
ViewController.m
#import “ViewController.h”
@interface ViewController ()
@end
@implementation ViewController
– (void)viewDidLoad {
[super viewDidLoad];
NSURLSessionConfiguration *sessionConfiguration = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:sessionConfiguration delegate:self delegateQueue:nil];
NSURLSessionDownloadTask *downloadTask = [session downloadTaskWithURL:[NSURL URLWithString:@”https://i.ytimg.com/vi/QGiJFumHUPo/maxresdefault.jpg”]];
[downloadTask resume];
// Do any additional setup after loading the view, typically from a nib.
}
– (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
– (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location {
NSData *data = [NSData dataWithContentsOfURL:location];
dispatch_async(dispatch_get_main_queue(), ^{
//[self.progressView setHidden:YES];
[self.imageView setImage:[UIImage imageWithData:data]];
});
}
– (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didResumeAtOffset:(int64_t)fileOffset expectedTotalBytes:(int64_t)expectedTotalBytes {
}
– (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite {
float progress = (double)totalBytesWritten / (double)totalBytesExpectedToWrite;
dispatch_async(dispatch_get_main_queue(), ^{
[self.progressView setProgress:progress];
});
}
@end
Download Sample Project From Github
iOS Development Objective C 
