#define HMGlobalQueue dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)

#define HMMainQueue dispatch_get_main_queue()

#import "HMViewController.h"

@interface HMViewController ()

@property (weak, nonatomic) IBOutlet UIButton *button;

@property (weak, nonatomic) IBOutlet UIImageView *newImageView;

@end

@implementation HMViewController

- (void)viewDidLoad

{

    [super viewDidLoad];

    [self newImageView];

//    NSObject *obj = [NSObject new];

//

//    [[NSObject alloc] init];

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

}

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

{

    dispatch_async(HMGlobalQueue, ^{

        NSLog(@"donwload---%@", [NSThread currentThread]);

        // 1.子线程下载图片

        NSURL *url = [NSURL URLWithString:@"http://d.hiphotos.baidu.com/image/pic/item/37d3d539b6003af3290eaf5d362ac65c1038b652.jpg"];

        NSData *data = [NSData dataWithContentsOfURL:url];

        UIImage *image = [UIImage imageWithData:data];

        // 2.回到主线程设置图片

        dispatch_async(HMMainQueue, ^{

            NSLog(@"setting---%@ %@", [NSThread currentThread], image);

            [self.button setImage:image forState:UIControlStateNormal];

        });

    });

}

@end