1 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
2 {
3 dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
4 dispatch_async(queue, ^{
5 NSLog(@"--download--%@", [NSThread currentThread]);
6 // 下载图片
7 NSURL *url = [NSURL URLWithString:@"http://news.baidu.com/z/resource/r/image/2014-06-22/2a1009253cf9fc7c97893a4f0fe3a7b1.jpg"];
8 NSData *data = [NSData dataWithContentsOfURL:url]; // 这行会比较耗时
9 UIImage *image = [UIImage imageWithData:data];
10
11 // 回到主线程显示图片
12 dispatch_async(dispatch_get_main_queue(), ^{
13 NSLog(@"--imageView--%@", [NSThread currentThread]);
14 self.imageView.image = image;
15 });
16 });
17 }
