我是iPhone的iOS开发新手。我希望在iOS中的滚动视图中放大和缩小(图像的对称缩放)图像。这是我的代码:在此代码中,我在滚动视图(ZoomScrollView)中获取了一个图像视图,在另一个内部滚动了视图Scrollview(scrollView_Gallery)。提前感谢..
// // ZoomGalleryViewController.m
scrollView_Gallery.backgroundColor = [UIColor yellowColor];
scrollView_Gallery.delegate = self;
scrollView_Gallery.pagingEnabled = YES;
scrollView_Gallery.userInteractionEnabled = YES;
scrollView_Gallery.showsHorizontalScrollIndicator = NO;
scrollView_Gallery.showsVerticalScrollIndicator = NO;
[self.view addSubview:scrollView_Gallery];
if(UI_USER_INTERFACE_IDIOM()==UIUserInterfaceIdiomPhone)
{
[scrollView_Gallery setContentSize:CGSizeMake(self.view.frame.size.width*[arrayUrl count],self.view.frame.size.height)];
}
else if(UI_USER_INTERFACE_IDIOM()==UIUserInterfaceIdiomPad)
{
[scrollView_Gallery setContentSize:CGSizeMake([[UIScreen mainScreen] bounds].size.width*[arrayUrl count],[[UIScreen mainScreen] bounds].size.height)];
}
for (int i = 0; i < [arrayUrl count]; i++)
{
zoomScrollView = [[ZoomScrollView alloc]init];
zoomScrollView.backgroundColor = [UIColor redColor];
[zoomScrollView setContentSize:CGSizeMake(zoomScrollView.contentSize.width,zoomScrollView.frame.size.height)];
CGRect frame = scrollView_Gallery.frame;
frame.origin.x = (frame.size.width)* i;
frame.origin.y = 0;
zoomScrollView.frame = frame;
zoomScrollView.imageView.contentMode = UIViewContentModeScaleAspectFit;
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:[[arrayUrl objectAtIndex:i]objectForKey:@"photopath"]]];
__weak UIImageView *weakImageView = zoomScrollView.imageView;
zoomScrollView.imageView.tag = i;
zoomScrollView.ZOOM_VIEW_TAG = zoomScrollView.imageView.tag;
[zoomScrollView.imageView setImageWithURLRequest:request
placeholderImage:nil
success:^(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image)
{
NSLog(@"image=%f,imageheight=%f",image.size.width,image.size.height);
UIImageView *strongImageView = weakImageView; // make local strong reference to protect against race conditions
strongImageView.frame = CGRectMake(0,0,image.size.width*image.scale, image.size.height*image.scale);
strongImageView.center = scrollView_Gallery.center;
NSLog(@"image11 = %f, imageheight11 = %f",image.size.width*image.scale, image.size.height*image.scale);
NSLog(@"imageScale = %f",image.scale);
if (!strongImageView) return;
[UIView transitionWithView:strongImageView
duration:0.3
options:UIViewAnimationOptionTransitionCrossDissolve animations:^{
strongImageView.image = image;
}
completion:NULL];
//[scrollView_Gallery setContentOffset:CGPointMake(strongImageView.frame.size.width * (indexNumber+1), 0)];
}failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error){
NSLog(@"Request failed with error: %@", error);
}];
[scrollView_Gallery addSubview:zoomScrollView];
[zoomScrollView setContentSize:CGSizeMake(zoomScrollView.contentSize.width,zoomScrollView.frame.size.height)];
if(UI_USER_INTERFACE_IDIOM()==UIUserInterfaceIdiomPhone)
{
[scrollView_Gallery setContentOffset:CGPointMake(self.view.frame.size.width * (indexNumber), 0)];
}
else if(UI_USER_INTERFACE_IDIOM()==UIUserInterfaceIdiomPad)
{
[scrollView_Gallery setContentOffset:CGPointMake([[UIScreen mainScreen] bounds].size.width * (indexNumber), 0)];
}
// ZoomScrollView.h//
#import <UIKit/UIKit.h>
@interface MRZoomScrollView : UIScrollView <UIScrollViewDelegate>
{
UIImageView *imageView;
}
@property (nonatomic, retain) UIImageView *imageView;
@end
// MRZoomScrollView.m //
#import "MRZoomScrollView.h"
#define MRScreenWidth CGRectGetWidth([UIScreen mainScreen].applicationFrame)
#define MRScreenHeight CGRectGetHeight([UIScreen mainScreen].applicationFrame)
@interface MRZoomScrollView (Utility)
- (CGRect)zoomRectForScale:(float)scale withCenter:(CGPoint)center;
@end
@implementation MRZoomScrollView
@synthesize imageView;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.delegate = self;
self.frame = CGRectMake(0, 0, MRScreenWidth, MRScreenHeight);
[self initImageView];
}
return self;
}
- (void)initImageView
{
imageView = [[UIImageView alloc]init];
// The imageView can be zoomed largest size
imageView.frame = CGRectMake(0, 0, MRScreenWidth * 2.5, MRScreenHeight * 2.5);
imageView.userInteractionEnabled = YES;
[self addSubview:imageView];
[imageView release];
// Add gesture,double tap zoom imageView.
UITapGestureRecognizer *doubleTapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleDoubleTap:)];
[doubleTapGesture setNumberOfTapsRequired:2];
[imageView addGestureRecognizer:doubleTapGesture];
[doubleTapGesture release];
float minimumScale = self.frame.size.width / imageView.frame.size.width;
[self setMinimumZoomScale:minimumScale];
[self setZoomScale:minimumScale];
}
#pragma mark - Zoom methods
- (void)handleDoubleTap:(UIGestureRecognizer *)gesture
{
float newScale = self.zoomScale * 1.5;
CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gesture locationInView:gesture.view]];
[self zoomToRect:zoomRect animated:YES];
}
- (CGRect)zoomRectForScale:(float)scale withCenter:(CGPoint)center
{
CGRect zoomRect;
zoomRect.size.height = self.frame.size.height / scale;
zoomRect.size.width = self.frame.size.width / scale;
zoomRect.origin.x = center.x - (zoomRect.size.width / 2.0);
zoomRect.origin.y = center.y - (zoomRect.size.height / 2.0);
return zoomRect;
}
#pragma mark - UIScrollViewDelegate
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return imageView;
}
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale
{
[scrollView setZoomScale:scale animated:NO];
}
答案 0 :(得分:3)
您可以使用 UIScrollView 并启用enabledZoom
来启用。
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imageView;
}
在viewDidLoad方法中粘贴此代码
- (void)viewDidLoad {
[super viewDidLoad];
self.scrollView.minimumZoomScale=0.5;
self.scrollView.maximumZoomScale=6.0;
self.scrollView.contentSize=CGSizeMake(1280, 960);
self.scrollView.delegate=self;
}
答案 1 :(得分:1)
查看this教程,对我有帮助:
答案 2 :(得分:0)
假设您有一个属性scrollView,请在视图控制器的viewDidLoad或viewWillAppear方法中尝试以下代码:
self.scrollView.minimumZoomScale=1.0;
self.scrollView.maximumZoomScale=2.0;
self.scrollView.contentSize=self.scrollView.frame.size;
self.scrollView.bounces=YES;
self.scrollView.delegate=self;
让您的视图控制器符合UIScrollViewDelegate协议。并实现委托方法:
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imageView;// return the imageView inside the scrollview which has to be scaled.
}