关于iPad+iPhone上，图片放大缩小时都能点击此区域

比如我们有个中国地图，在北京这个区域放了一个button，当这张地图放大和缩小的时候，我们都能点击这个button触发北京里面的事件。

方法有点笨。 总的来说就是计算放到后图片的尺寸，然后算出放大倍数。把初始坐标放大

设两个变量

float x;

float y;

- (void)viewDidLoad {
[super viewDidLoad];
x = 1;
y = 1;

UIImage *image = [UIImage imageNamed:@"index_big.jpg"];
imageView = [[UIImageView alloc] initWithImage:image];
imageView.frame = CGRectMake(0, 0, 1024, 768);
imageView.userInteractionEnabled = YES;

scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
scrollView.contentSize = CGSizeMake(imageView.frame.size.width, imageView.frame.size.height);
scrollView.maximumZoomScale = 3.0;
scrollView.minimumZoomScale = 1.0;
scrollView.delegate = self;
[self.view addSubview:scrollView];
[self.view bringSubviewToFront:scrollView];

[scrollView addSubview:imageView];
[scrollView bringSubviewToFront:imageView];
}

- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:YES];
uaButton = [UIButton buttonWithType:UIButtonTypeCustom];
uaButton.frame = CGRectMake(731*x, 235*y, 130, 60);
[uaButton setTag:1];
[uaButton addTarget:self action:@selector(clickButton:) forControlEvents:UIControlEventTouchUpInside];
[imageView addSubview:uaButton];
}

#pragma mark -
#pragma mark view zoom
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return imageView;
}

- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale{
NSLog(@"scrollViewDidEndZooming  width:%f, height:%f",imageView.frame.size.width, imageView.frame.size.height);
x = imageView.frame.size.width/1024;
y = imageView.frame.size.height/768;
}