我编写了以下代码以在滚动视图中添加可选缩略图列表
while(element = [enumerator nextObject])
{
// Do your thing with the object.
MenuUrl *menuUrl = (MenuUrl *) element;
if([menuUrl.index isEqualToString:@"menu_url"] || [menuUrl.index isEqualToString:@"photos_url"])
continue;
//NSLog(@"%@", menuUrl.index);
NSString *url = menuUrl.image.thumbUrl;
dispatch_queue_t download_queue = dispatch_queue_create("image downloader", NULL);
dispatch_async(download_queue, ^{
UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString: url]]];
CGRect imageframe;
imageframe.origin.x = 15+ 101.6*(imageNumber % 3);
//NSLog(@"%d", imageNumber);
imageframe.origin.y = 101.6*(imageNumber / 3);
imageframe.size.height = 86.6;
imageframe.size.width = 86.6;
dispatch_async(dispatch_get_main_queue(), ^{
UIButton *myButton0 = [[UIButton alloc] initWithFrame:imageframe];
myButton0.tag = imageNumber;
[myButton0 setBackgroundImage:image forState:UIControlStateNormal];
[myButton0 addTarget:self action:@selector(showDetailImage) forControlEvents:UIControlEventTouchUpInside];
[scrollView addSubview:myButton0];
});
});
dispatch_release(download_queue);
imageNumber = imageNumber + 1;
}
[self.view addSubview:scrollView];
现在,每当我选择任何缩略图时,都会收到 EXC_BAD_ACCESS 错误。为什么会这样?