尽管 contentSize 小于 UIImageView，但 UIScrollView 不滚动

问题描述

所以我有一个 UIImageView 作为 UIScrollView 的子视图，我将 contentSize 设置为小于 UIImageView 宽度和高度，但是它不允许我滚动.. 这是为什么?这是一些代码:

So I have a UIImageView as a subview of UIScrollView, I've set the contentSize to be smaller than the UIImageView width and height, however it doesn't allow me to scroll.. why is this? Here's some code:

UIImage * image = [UIImage imageWithData:data];
                UIImageView * imgView = [[UIImageView alloc] initWithImage:image];
                [imgView setUserInteractionEnabled:YES];
                //[imgView setContentMode:UIViewContentModeScaleAspectFill];
                [imgView setBackgroundColor:[UIColor clearColor]];
                [imgView setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight];
                [imgView setFrame:CGRectMake(0, 0, imgView.frame.size.width, imgView.frame.size.height)];

                CGRect imgFrame;
                imgFrame.size.width = originalImageSize.width;
                imgFrame.size.height = originalImageSize.height;
                imgFrame.origin.x = imageOriginPoint.x;
                imgFrame.origin.y = imageOriginPoint.y;

                UIScrollView * imgScrollView = [[UIScrollView alloc] initWithFrame:imgFrame];
                [imgScrollView setScrollEnabled:YES];
                [imgScrollView setClipsToBounds:YES];
                [imgScrollView addSubview:imgView];
                [imgScrollView setBackgroundColor:[UIColor clearColor]];


  [imgScrollView setFrame:imgFrame];
                [imgScrollView setContentSize:CGSizeMake(200, 200)];

SCROLL VIEW CONTENT SIZE WIDTH IS 200.000000 AND HEIGHT CONTENT SIZE IS 200.000000
UIIMAGE VIEW WIDTH IS 2240.225830 AND HEIGHT IS 2240.225830
SCROLL VIEW FRAME WIDTH IS 768.000000 AND SCROLL VIEW FRAME HEIGHT IS 768.000061

有什么想法吗?

推荐答案

那是因为你的滚动视图边界的大小大于你的内容大小.内容大小需要是图像视图的实际大小，可见大小由框架/边界设置.我猜你想在 {200, 200} 大小的矩形中滚动图像?试试这个:

That's because that your size of bounds of scroll view is larger than your content size. The content size need to be the actual size of image view, and the visible size is set by frame / bounds. I guess you want to scroll a image in a {200, 200} sized rect? Try this:

        UIScrollView * imgScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)]; // this is your visible rect
        [imgScrollView setScrollEnabled:YES];
        [imgScrollView setClipsToBounds:YES];
        [imgScrollView addSubview:imgView];
        [imgScrollView setBackgroundColor:[UIColor yellowColor]];

        [imgScrollView setContentSize:imgFrame.size]; // this is your image view size