通过 UIPinchGestureRecognizer 设置滚动视图相对于缩放变换的内容大小
Set content size of scrollview relative to transform on zooming by UIPinchGestureRecognizer
我有滚动视图并添加了 UIPinchGestureRecognizer
到滚动视图。现在在手势事件上我有放大或缩小滚动视图,它的处理动作如下:
static float lastScale = 1.0;
- (void)handlePinchGesture:(UIPinchGestureRecognizer *)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
}
}
我想在此方法中更改 contentSize。现在,我的问题是如何设置滚动视图内容大小,以便在缩小后我可以滚动查看滚动视图中的所有内容。
请帮忙。
@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 *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return container;
}
我有滚动视图并添加了 UIPinchGestureRecognizer
到滚动视图。现在在手势事件上我有放大或缩小滚动视图,它的处理动作如下:
static float lastScale = 1.0;
- (void)handlePinchGesture:(UIPinchGestureRecognizer *)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
}
}
我想在此方法中更改 contentSize。现在,我的问题是如何设置滚动视图内容大小,以便在缩小后我可以滚动查看滚动视图中的所有内容。
请帮忙。
@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 *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return container;
}