对于UIScrollView的变焦不工作(The zoom for uiscrollview isn

我不明白为什么滚动视图不工作，因为我跟着从教程建议。

我创建UIScrollView包含一个UIImageView和我还添加方法

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

和UIScrollViewDelegate的接口，但它不工作。

下面是代码UIScrollView ：

 imgv = [[UIImageView alloc]
                     initWithFrame:CGRectMake(0, 0, 1000, 500)];
 imgv.image = [UIImage imageWithData:retrievedData];

 scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 800, 800)];
 scrollView setContentSize:CGSizeMake(imgv.image.size.width, imgv.image.size.height)];
 scrollView.maximumZoomScale = 4;
 scrollView.minimumZoomScale = 1;
 [scrollView setScrollEnabled:YES];
 scrollView.clipsToBounds = YES;
 scrollView.delegate = self;

self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(hideImageView)];

 [scrollView addSubview:imgv];
 [view addSubview:scrollView];

我会感激，如果有人可以找出问题可能是什么。

Answer 1:

您需要返回imgv在您的委托方法viewForZoomingInScrollView： ：

- (UIView *) viewForZoomingInScrollView:(UIScrollView *) view {
    return imgv;
}

Answer 2:

你必须在ImageView的添加为子视图滚动视图

[scrollView addSubview:imgv];

Answer 3:

我相信你是忘记正确设置你的ImageView的框架

self.imageView.frame=CGRectMake(0, 0, self.imageView.image.size.width, self.imageView.image.size.height);

文章来源: The zoom for uiscrollview isn't working