#import "HMViewController.h"

#import "HMImageDownloader.h"

@interface HMViewController ()

//@property (nonatomic, strong) HMImageDownloader *downloader;

@end

@implementation HMViewController

- (void)viewDidLoad

{

    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.

//    self.downloader = [[HMImageDownloader alloc] init];

} 

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{

    NSLog(@"----touchesBegan");

    static dispatch_once_t onceToken;

    dispatch_once(&onceToken, ^{  //只能执行一次

        NSLog(@"----once");

        HMImageDownloader *downloader = [[HMImageDownloader alloc] init];

        [downloader download];

    });

}

@end