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标题: ios - 通过 UIPinchGestureRecognizer 设置相对于缩放变换的 ScrollView 的内容大小 [打印本页]

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作者: 菜鸟教程小白    时间: 2022-12-13 12:39
标题: ios - 通过 UIPinchGestureRecognizer 设置相对于缩放变换的 ScrollView 的内容大小

我有 ScrollView 并将 UIPinchGestureRecognizer 添加到 ScrollView 。现在在手势事件中，我放大或缩小 ScrollView ，其句柄操作如下:

static float lastScale = 1.0;

- (void)handlePinchGestureUIPinchGestureRecognizer *)gestureRecognizer
{

    if([gestureRecognizer state] == UIGestureRecognizerStateBegan) {
    // Reset the last scale, necessary if there are multiple objects with different scales
        lastScale = [gestureRecognizer scale];
    }

    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged)
    {
        CGFloat currentScale = [[[gestureRecognizer view].layer valueForKeyPath"transform.scale"] floatValue];

        // Constants to adjust the max/min values of zoom
        const CGFloat kMaxScale = 2.0;
        const CGFloat kMinScale = 1.0;

        CGFloat newScale = 1 -  (lastScale - [gestureRecognizer scale]);
        newScale = MIN(newScale, kMaxScale / currentScale);
        newScale = MAX(newScale, kMinScale / currentScale);
        CGAffineTransform transform = CGAffineTransformScale([[gestureRecognizer view] transform], newScale, newScale);
        [gestureRecognizer view].transform = transform;

        lastScale = [gestureRecognizer scale];  // Store the previous scale factor for the next pinch gesture call
    }
}

我想在这个方法中改变 contentSize。现在，我的问题是如何设置 ScrollView 的内容大小，以便在缩小后我可以滚动查看 ScrollView 中的所有内容。

请帮忙。

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Best Answer-推荐答案

@interface HorizontalScrollView ()
{
    UIView *container;
}
@end

@implementation HorizontalScrollView
@synthesize scrlView;

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    container = [[UIView alloc]initWithFrame:CGRectMake(0, 0, self.scrlView.frame.size.width, self.scrlView.frame.size.height)];


    UIImage *image = [UIImage imageNamed"1.jpeg"];
    UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
    CGRect rect = imageView.frame;
    rect.size.height = 215;
    rect.size.width = self.scrlView.frame.size.width;
    rect.origin = CGPointMake(0, 0);
    imageView.frame = rect;
    [container addSubview:imageView];

    [scrlView addSubview:container];

    self.scrlView.minimumZoomScale=1.0;
    self.scrlView.maximumZoomScale=6.0;
    self.scrlView.delegate=self;

    // set the content size so it can be scrollable
    [self.scrlView setContentSize:CGSizeMake(1*self.scrlView.frame.size.width, 0)];
}

- (UIView *)viewForZoomingInScrollViewUIScrollView *)scrollView
{
    return container;
}

关于ios - 通过 UIPinchGestureRecognizer 设置相对于缩放变换的 ScrollView 的内容大小，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34281827/

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