UIscrollview if imagesview how to add zoom? - iphone

Question

Hello everyone i need to add zoom in uiscrollview containing several uiimageviews. Here is my code how I am doing it but its not working properly
- (void)setupPage
{
scrollView.delegate = self;
[self.scrollView setBackgroundColor:[UIColor blackColor]];
[scrollView setCanCancelContentTouches:NO];
scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
scrollView.clipsToBounds = YES;
scrollView.scrollEnabled = YES;
scrollView.pagingEnabled = YES;
NSUInteger nimages = 0;
CGFloat cx = 0;
for (; ; nimages++) {
//Maquette final_Print 2.png
NSString *imageName = [NSString stringWithFormat:#"rint %d.png", (nimages + 1)];
UIImage *image = [UIImage imageNamed:imageName];
if (image == nil) {
break;
}
imageView = [[UIImageView alloc] initWithImage:image];
[imageView setContentMode:UIViewContentModeScaleToFill];
CGRect rect = imageView.frame;
rect.size.height = 1004;
rect.size.width = 768;
rect.origin.x = ((scrollView.frame.size.width - 768) / 2) + cx;
rect.origin.y = ((scrollView.frame.size.height - 1004) / 2);
imageView.frame = rect;
[scrollView addSubview:imageView];
[imageView release];
cx += scrollView.frame.size.width;
}
[scrollView setContentSize:CGSizeMake(cx, 1004)];
scrollView.minimumZoomScale = scrollView.frame.size.width / 768;
scrollView.maximumZoomScale = 2.0;
[scrollView setZoomScale:scrollView.minimumZoomScale];
}
// Code for handling zooming :
#pragma mark -
#pragma mark UIScrollView ZOOM
//- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
// imageView.frame = [self centeredFrameForScrollView:scrollView andUIView:imageView];;
//}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return imageView;
}
- (CGRect)centeredFrameForScrollView:(UIScrollView *)scroll andUIView:(UIView *)rView {
CGSize boundsSize = scroll.bounds.size;
CGRect frameToCenter = rView.frame;
// center horizontally
if (frameToCenter.size.width < boundsSize.width) {
frameToCenter.origin.x = (boundsSize.width - frameToCenter.size.width) / 2;
}
else {
frameToCenter.origin.x = 0;
}
// center vertically
if (frameToCenter.size.height < boundsSize.height) {
frameToCenter.origin.y = (boundsSize.height - frameToCenter.size.height) / 2;
}
else {
frameToCenter.origin.y = 0;
}
return frameToCenter;
}
When I am trying to zoom its not working as expected. And also i cannot swipe left or right...

Answer 1

.m File
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.theImageView;
}
- (CGRect)centeredFrameForScrollView:(UIScrollView *)scroll andUIView:(UIView *)rView {
CGSize boundsSize = scroll.bounds.size;
CGRect frameToCenter = rView.frame;
// center horizontally
if (frameToCenter.size.width < boundsSize.width) {
frameToCenter.origin.x = (boundsSize.width - frameToCenter.size.width) / 2;
}
else {
frameToCenter.origin.x = 0;
}
// center vertically
if (frameToCenter.size.height < boundsSize.height) {
frameToCenter.origin.y = (boundsSize.height - frameToCenter.size.height) / 2;
}
else {
frameToCenter.origin.y = 0;
}
return frameToCenter;
}
-(void)scrollViewDidZoom:(UIScrollView *)scrollView
{
self.theImageView.frame = [self centeredFrameForScrollView:self.theScrollView andUIView:self.theImageView];
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[self.resourceData setLength:0];
self.filesize = [NSNumber numberWithLongLong:[response expectedContentLength]];
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[self.resourceData appendData:data];
NSNumber *resourceLength = [NSNumber numberWithUnsignedInteger:[self.resourceData length]];
self.progressBar.progress = [resourceLength floatValue] / [self.filesize floatValue];
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
self.theImage = [[UIImage alloc]initWithData:resourceData];
self.theImageView.frame = CGRectMake(0, 0, self.theImage.size.width, self.theImage.size.height);
self.theImageView.image = self.theImage;
self.theScrollView.minimumZoomScale = self.theScrollView.frame.size.width / self.theImageView.frame.size.width;
self.theScrollView.maximumZoomScale = 2.0;
[self.theScrollView setZoomScale:self.theScrollView.minimumZoomScale];
self.theScrollView.contentSize = self.theImageView.frame.size;
self.theLabel.hidden = YES;
self.progressBar.hidden = YES;
}
-(void)setImageInImageView
{
NSURLRequest *req = [[NSURLRequest alloc]initWithURL:[NSURL URLWithString:self.imageLink]];
NSURLConnection *conn = [[NSURLConnection alloc]initWithRequest:req delegate:self];
if (conn)
{
self.resourceData = [NSMutableData data];
}
else
{
NSLog(#"Connection failed: IMageViewerViewController");
}
}
-(void)loadView
{
self.filesize = [[NSNumber alloc]init];
self.progressBar = [[UIProgressView alloc]initWithProgressViewStyle:UIProgressViewStyleBar];
self.progressBar.frame = CGRectMake(20, 240, 280, 40);
[self.progressBar setProgress:0.0];
self.theImageView = [[[UIImageView alloc]initWithFrame:[[UIScreen mainScreen]applicationFrame]]autorelease];
self.theScrollView = [[[UIScrollView alloc]initWithFrame:[[UIScreen mainScreen]applicationFrame]]autorelease];
self.theScrollView.delegate = self;
[self.theScrollView addSubview:self.theImageView];
self.view = self.theScrollView;
self.theLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, 200, 320, 40)];
self.theLabel.font = [UIFont boldSystemFontOfSize:15.0f];
self.theLabel.text = #"Please wait, file is being downloaded";
self.theLabel.textAlignment = UITextAlignmentCenter;
self.theLabel.hidden = NO;
[self.view addSubview:self.progressBar];
[self.view bringSubviewToFront:self.progressBar];
[self.view addSubview:self.theLabel];
[self.view bringSubviewToFront:self. theLabel];
[self performSelectorOnMainThread:#selector(setImageInImageView) withObject:nil waitUntilDone:NO];
}
.h File
#interface ImageViewerViewController : UIViewController<UIScrollViewDelegate, NSURLConnectionDelegate, NSURLConnectionDataDelegate>
#property (nonatomic, retain) IBOutlet UIImageView *theImageView;
#property (nonatomic, retain) IBOutlet UIScrollView *theScrollView;
#property (nonatomic, retain) NSString *imageLink;
#property (nonatomic, retain) UIImage *theImage;
#property (nonatomic, retain) UILabel *theLabel;
#property (nonatomic, retain) UIProgressView *progressBar;
#property (nonatomic, retain) NSMutableData *resourceData;
#property (nonatomic, retain) NSNumber *filesize;
#end

Answer 2

All you need to do is add your UIImageView (or any view you want to zoom) inside your UIScrollView.
Set your maxZoomScale on your UIScrollView to any value higher than 1.0f.
Set yourself as the delegate of your UIScrollView and return the UIImageView in the viewForZooming delegate method.
That's it. No pinch gesture needed, no nothing. UIScrollView handles pinch zooming for you.