怎么做缩放图像xcode ??

Question

我有个问题.我有这个代码缩放不起作用.

- (void)viewDidLoad {

UIImage *image = [UIImage imageNamed:@"zoomimage.jpeg"];

CGRect yFrame = CGRectMake(0.0, 0.0, 320, 432);

imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0.0, 0.0, image.size.width, image.size.height)];
[imageView setImage:image];

scrollView = [[UIScrollView alloc] initWithFrame:yFrame];
[scrollView setScrollEnabled:YES];
[scrollView setBackgroundColor:[UIColor blackColor]];
[scrollView setContentSize:CGSizeMake(image.size.width, image.size.height)];
scrollView.minimumZoomScale = 0.4;
scrollView.maximumZoomScale = 4.0;
[scrollView setZoomScale:scrollView.minimumZoomScale];

[self.view addSubview:scrollView];
[self.view bringSubviewToFront:scrollView];

[scrollView addSubview:imageView];

}

Answer 1

首先,将scrollview的委托设置为您自己.

scrollView.delegate = self;

现在,UIScrollView在您的类中添加此委托方法以启用图像缩放.

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
  return imageView;
}