I am creating photo browser.
I create VC that will be display photo and it can zoom/zoom out it.
Also I create another VC that I use like a page control.
Now I can only page thought all photos and it works very good.
Also If I load image in my VC for single photo I can zoom/zoom out it.
Now my purpose is to combine it.
I want to have image pager VC that will be able go thought images and zoom/zoom out desire image. And then there is no space to zoom/zoom out it will be switch to other images.
I have tap gesture and pinch gesture in single image VC.
How can I separate this events? Or how can I achieve it?
My code for is
ImagePagerViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
[self createPages];
}
- (void)viewDidLayoutSubviews
{
[super viewDidLayoutSubviews];
[self updatePages];
}
- (void)createPages
{
for (NSUInteger i = 0; i < self.dataSource.count; i++)
{
NSURL *url = self.dataSource[i];
AttachmentViewController *attachmentViewController = [[AttachmentViewController alloc] initWithUserType:ImageViewer setActiveMode:None setInitialSeconds:NULL];
attachmentViewController.imageURL = url;
[self.scrollView insertSubview:attachmentViewController.view atIndex:self.views.count];
[self.views addObject:attachmentViewController.view];
}
}
- (void)updatePages
{
CGFloat w = ScreenWidth;
CGFloat h = ScreenHeight;
for (NSUInteger i = 0; i < self.views.count; i++)
{
UIView *view = self.views[i];
view.frame = CGRectMake(i * w, 0, w, h);
}
self.scrollView.contentSize = CGSizeMake(self.dataSource.count * w, h);
}
Related
I have a view controller with outlets of scrollview (initial size: 390, 170) and page control. I need it to display an image per page from my array. But i have unexpected result (see image below).
Images are not full-width and after 2nd page scrollView ends.
Here is code
- (void)viewDidLoad {
[super viewDidLoad];
//Put the names of our image files in our array.
imageArray = [[NSArray alloc] initWithObjects:#"header1.jpg", #"header2.jpg", #"header3.jpg", nil];
[self.articlesPageControll setNumberOfPages:imageArray.count];
for (int i = 0; i < [imageArray count]; i++) {
//We'll create an imageView object in every 'page' of our scrollView.
CGRect frame;
frame.origin.x = 390 * i;
frame.origin.y = 0;
frame.size = self.articlesScrollView.frame.size;
UIImageView *imageView = [[UIImageView alloc] initWithFrame:frame];
[imageView setContentMode:UIViewContentModeScaleToFill];
imageView.image = [UIImage imageNamed:[imageArray objectAtIndex:i]];
[self.articlesScrollView addSubview:imageView];
}
//Set the content size of our scrollview according to the total width of our imageView objects.
self.articlesScrollView.contentSize = CGSizeMake(self.articlesScrollView.frame.size.width * [imageArray count], 170);
}
- (void)scrollViewDidScroll:(UIScrollView *)sender
{
// Update the page when more than 50% of the previous/next page is visible
CGFloat pageWidth = self.articlesScrollView.frame.size.width;
int page = floor((self.articlesScrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
self.articlesPageControll.currentPage = page;
}
UPD: 3rd page with image actually exists, but it's impossible to scroll to this page
Thanks in advance!
Solution self.articlesScrollView.contentSize = CGSizeMake(390 * [imageArray count], 170);
I am showing around 50 Images In a scroll view and I am facing the memory issue, every time the Controller loads the memory usage increases and it goes over 200MB in the Instruments App.
.h file of my custom class
#import
#class AnimalGrid;
#protocol AnimalGridViewDelegate <NSObject>
-(void)animalGrid:(AnimalGrid*)animalgridview tappedAtIndex:(int)index andName:(NSString*)animalName;
#end
#interface AnimalGrid : UIView
#property(nonatomic, strong) UIImage *animalImage;
#property(nonatomic, copy) NSString *animalName;
#property(nonatomic) int animalTag;
#property (nonatomic, assign) id <AnimalGridViewDelegate> Delegate;
-(id)initGridWithFrame:(CGRect)frame andAnimalImage:(UIImage*)image andAnimalName:(NSString*)animalname andTag:(int)tag;
-(void)setFont:(UIFont*)font;
#end
.m file of my Custom Class
#import "AnimalGrid.h"
#implementation AnimalGrid
{
UIImageView *_contentView;
UILabel *_accessoryView;
UIImage *displayImage;
NSString *displayText;
}
#synthesize Delegate = _Delegate;
-(id)initGridWithFrame:(CGRect)frame andAnimalImage:(UIImage*)image andAnimalName:(NSString*)animalname andTag:(int)tag
{
self = [super initWithFrame:frame];
if (self) {
self.backgroundColor = [UIColor clearColor];
self.animalName = animalname;
self.animalTag = tag;
displayImage = image;
displayText = animalname;
CGFloat contentHeight = frame.size.height * 0.8;
if ( animalname == nil || animalname.length == 0)
contentHeight = frame.size.height;
CGFloat margin = 0;
if (displayImage.size.height < contentHeight)
{
margin = contentHeight - displayImage.size.height;
}
UIView *placeholderView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, frame.size.width, contentHeight)];
placeholderView.backgroundColor = [UIColor clearColor];
if (image.size.height > placeholderView.frame.size.height)
{
_contentView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, frame.size.width, placeholderView.frame.size.height)];
}else if (image.size.height < placeholderView.frame.size.height){
CGFloat margin = placeholderView.frame.size.height - image.size.height;
_contentView = [[UIImageView alloc]initWithFrame:CGRectMake(0, margin, frame.size.width, placeholderView.frame.size.height - margin)];
}
_contentView.backgroundColor = [UIColor clearColor];
_accessoryView = [[UILabel alloc]initWithFrame:CGRectMake(0, frame.size.height * 0.7, frame.size.width, frame.size.height-frame.size.height * 0.7)];
_accessoryView.numberOfLines = 2;
_accessoryView.backgroundColor = [UIColor clearColor];
_accessoryView.font = [UIFont fontWithName:#"HFFAirApparent" size:23];
_accessoryView.textColor = [UIColor orangeColor];
[placeholderView addSubview:_contentView];
[self addSubview:placeholderView];
if ( animalname != nil || animalname.length > 0)
[self addSubview:_accessoryView];
if(image)
_contentView.image = image;
_contentView.contentMode = UIViewContentModeScaleAspectFit;
_accessoryView.text = animalname;
_accessoryView.numberOfLines = 0;
[_accessoryView sizeToFit];
CGFloat w = self.bounds.size.width/2;
_accessoryView.frame = CGRectMake(w - (_accessoryView.frame.size.width/2), _accessoryView.frame.origin.y, _accessoryView.frame.size.width, _accessoryView.frame.size.height);
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(tapedOnImage:)];
singleTap.numberOfTapsRequired = 1;
singleTap.numberOfTouchesRequired = 1;
[_contentView addGestureRecognizer:singleTap];
_contentView.userInteractionEnabled = YES;
self.userInteractionEnabled = YES;
}
return self;
}
-(void)setFont:(UIFont*)font
{
_accessoryView.font = font;
}
-(void)tapedOnImage:(id)sender
{
if ([_Delegate respondsToSelector:#selector(animalGrid:tappedAtIndex:andName:)]) {
[_Delegate animalGrid:self tappedAtIndex:self.animalTag andName:self.animalName];
}
}
#end
And this is how I am creating the Object of my custom class and showing them over Scroll View, In my Controller file I am using following methods
-(void)setGridAnimals
{
#try {
[self creatingGridsWithCompletion:^(BOOL done, NSMutableArray *arr)
{
for (int i = 0; i < arr.count; i++)
{
UIView *gView = [arr objectAtIndex:i];
[gridScrollView addSubview:gView];
}
gridScrollView.scrollEnabled = YES;
gridScrollView.pagingEnabled = YES;
gridScrollView.bounces = YES;
gridScrollView.contentSize = CGSizeMake(gridScrollView.frame.size.width, gridScrollView.frame.size.height*arr.count);
[aView hideIndicatorView:YES];
}];
}
#catch (NSException *exception) {
NSLog(#" Exception is = %# ",exception.description);
}
#finally {
}
}
-(void)creatingGridsWithCompletion:(completionBlock)complete
{
#autoreleasepool {
NSMutableArray *pageArray = [NSMutableArray new];
int rowcount = 3;
int columncount = 5;
CGFloat width = gridScrollView.frame.size.width/columncount - 5;
CGFloat height = gridScrollView.frame.size.height/rowcount - 5;
int pagecount = gridAnimalArray.count/(rowcount*columncount);
if (gridAnimalArray.count%(rowcount*columncount))
{
pagecount += 1;
}
//pagecount = 1;
int x = 0;
for (int i = 0; i < pagecount; i++)
{
UIView *page = [[UIView alloc]initWithFrame:CGRectMake(0, x, gridScrollView.frame.size.width, gridScrollView.frame.size.height)];
for (int j = 0; j < rowcount; j++)
{
for (int k = 0; k < columncount; k++)
{
int tag = (i*(rowcount*columncount))+(j*columncount)+k+1;
if (tag > gridAnimalArray.count)
{
break;
}
YEAnimal *animal = [gridAnimalArray objectAtIndex:tag-1];
NSString *name = [[animal.GridName componentsSeparatedByString:#"."] objectAtIndex:0];
UIImage *gridImg;
if ([[NSFileManager defaultManager]fileExistsAtPath:[[NSBundle mainBundle] pathForResource:name ofType:#"png"]])
{
NSString * imgpath= [ [ NSBundle mainBundle] pathForResource:name ofType:#"png"];
gridImg=[UIImage imageWithContentsOfFile: imgpath];
}else if ([[NSFileManager defaultManager]fileExistsAtPath:[[NSBundle mainBundle] pathForResource:name ofType:#"jpg"]])
{
NSString * imgpath= [ [ NSBundle mainBundle] pathForResource:name ofType:#"jpg"];
gridImg=[UIImage imageWithContentsOfFile: imgpath];
}
AnimalGrid *grid = [[AnimalGrid alloc]initGridWithFrame:CGRectMake((k * width)+5, (j*height), width, height) andAnimalImage:gridImg andAnimalName:animal.SpeciesName andTag:tag];
grid.backgroundColor = [self getColor];
[grid setDelegate:self];
[page addSubview:grid];
}
}
[pageArray addObject:page];
x += gridScrollView.frame.size.height;
}
complete(YES,pageArray);
}
}
This is how the Grid Looks : http://s17.postimg.org/x9xdfl4j3/i_OS_Simulator_Screen_Shot_Mar_3_2015_1_54_45_P.png
So, far I came to know that I should use [UIImage imageWithContentsOfFile:] instead of [UIImage imageNamed:] to load the image, but still it does not help me.
Is there any way that I can free the Memory by releasing the ImageViews
Thanks.
There are several aproaches possible, depending on the layout of your view. How does it look like?
However, you can use a table to display the pictures in or use a collection. Actually a collection is made for that.
If you want to stick with the scroll view, then these 50 views are hardly visible at once. You could actually set their images just before the each view comes into sight and remove the images (set .image to nil) when the view moves off screen.
An App that I made recenly it is designed in a way that only one and exactly one of the images is visible full screen. When the user scrolls its neighbour image comes into view. (paging mechanism)
In my view the number of possible views is inpredictable. Although that is achievable with a collection too, I went for a scroll view.
In that view I designed the hosting scroll view in a way that it is just large enough to hold three views. The middle view of them is visible on screen. (Which exceptions applied when the very first or last - if any - view is displayed).
When the users scrolls just far enough for the neighbour view to be fully visible then I reset the scrollview so that its middle is visible again, move the view to the middle that just became visible, move the formerly visible view to the outer end and fill the other incoming end with a new view.
That allows for endless scrolling with not need to hold more than 4 images in memory at once. (4: the one that just moved off, the two that are shifted within the scroll view and the new one are allocated within the same method at a time.)
My app continues to increase in 'live bytes' by about 600kb every time I scroll to a new image. I am loading my images lazily, meaning only 3 at a time, into a UIScrollView that pages horizontally. I have run Xcode instruments and I believe I have tracked the problem to this line:
newPageView = [[UIImageView alloc] initWithImage:[self.album objectAtIndex:page]];
Every page that gets loaded creates a new UIImageView instance, and for some reason, the space is held in memory. I am using ARC and XCode5. Since there is no way to 'dealloc' objects in ARC, what is the best way to free up this memory?
Here's a snapshot of my instruments showing the images that keep taking up the memory:
I have seen this question proposed in other areas online but could not find an answer that helped. I'm fairly new to coding but very willing to learn, any references would be greatly appreciated! thanks!
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
self.pageCount = self.album.count;
// Set up the array to hold the views for each page
self.pageViews = [[NSMutableArray alloc] init];
for (NSInteger i = 0; i < self.pageCount; ++i) {
[self.pageViews addObject:[NSNull null]];
}
NSInteger p = self.page;
CGFloat w = self.scrollView.bounds.size.width;
[self.scrollView setContentOffset:CGPointMake(p*w,0) animated:YES];
// Set up the content size of the scroll view
CGSize pagesScrollViewSize = self.scrollView.frame.size;
self.scrollView.contentSize = CGSizeMake(pagesScrollViewSize.width * self.pageCount, pagesScrollViewSize.height);
// Load the initial set of pages that are on screen
[self loadVisiblePages];
}
- (void)loadVisiblePages {
// First, determine which page is currently visible
CGFloat pageWidth = self.scrollView.frame.size.width;
NSInteger page = (NSInteger)floor((self.scrollView.contentOffset.x * 2.0f + pageWidth) / (pageWidth * 2.0f));
// Keeps track of which image is showing, for passing to child view controller
self.currentImage = [self.album objectAtIndex:page];
self.title =[NSString stringWithFormat:#"%d of %d", [self.album indexOfObject:self.currentImage]+1, self.pageCount];
// Work out which pages we want to load
NSInteger firstPage = page - 1;
NSInteger lastPage = page + 1;
// Purge anything before the first page
for (NSInteger i=0; i<firstPage; i++) {
[self purgePage:i];
}
for (NSInteger i=firstPage; i<=lastPage; i++) {
[self loadPage:i];
}
for (NSInteger i=lastPage+1; i<self.pageCount; i++) {
[self purgePage:i];
}
}
- (void)loadPage:(NSInteger)page {
if (page < 0 || page >= self.pageCount) {
// If it's outside the range of what we have to display, then do nothing
return;
}
// Load an individual page, first seeing if we've already loaded it
UIView *pageView = [self.pageViews objectAtIndex:page];
// create an instance of imageView to be used as the newPageView
UIImageView *newPageView;
if ((NSNull*)pageView == [NSNull null]) {
CGRect frame = self.scrollView.bounds;
frame.origin.x = frame.size.width * page;
frame.origin.y = 0.0f;
newPageView = [[UIImageView alloc] initWithImage:[self.album objectAtIndex:page]];
newPageView.contentMode = UIViewContentModeScaleAspectFit;
newPageView.frame = frame;
[self.scrollView addSubview:newPageView];
[self.pageViews replaceObjectAtIndex:page withObject:newPageView];
}
}
- (void)purgePage:(NSInteger)page {
if (page < 0 || page >= self.pageCount) {
// If it's outside the range of what we have to display, then do nothing
return;
}
// Remove a page from the scroll view and reset the container array
UIView *pageView = [self.pageViews objectAtIndex:page];
if ((NSNull*)pageView != [NSNull null]) {
[pageView removeFromSuperview];
[self.pageViews replaceObjectAtIndex:page withObject:[NSNull null]];
[self.album replaceObjectAtIndex:page withObject:[NSNull null]];
}
}
#pragma mark - UIScrollViewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
[self loadVisiblePages];
}
ARC tries to release memory automatically so you don't have to worry about doing so.
However, you can kind of 'mark' objects so they can be released by 'niling' them:
yourobject = nil;
this kind of tells the IOS device that the object is not being used and can be released. If you're loading images into a scrollview, that means as the user scrolls down, there is content still in memory that is not on-screen and therefore is not needed. You can get rid of these images and then load them again when the scrollview gets near a certain point.
You might find an answer in this question (which is very similar to yours) helpful: Memory pressure in app
It's difficult to give an answer without see your code, but i suppose when you speak about "Lazy loading", you mean you only add your image to the scrollview when you need. But are you removing the images from the scrollview when they are not displayed?
I don't know which kind of display you want, but take a look on UICollectionView. Collection view manage the memory itself and only display cells when needed and UICollectionViewLayout allows you to customize the collection view.
I've changed my code to resize the images as they are loaded as followed:
- (void)loadPage:(NSInteger)page {
if (page < 0 || page >= self.pageCount) {
// If it's outside the range of what we have to display, then do nothing
return;
}
// Load an individual page, first seeing if we've already loaded it
UIView *pageView = [self.pageViews objectAtIndex:page];
// create an instance of imageView to be used as the newPageView
UIImageView *newPageView;
if ((NSNull*)pageView == [NSNull null]) {
CGRect frame = self.scrollView.bounds;
frame.origin.x = frame.size.width * page;
frame.origin.y = 0.0f;
self.resizeImage = [self.album objectAtIndex:page];
UIImage *theImage = [self resizeImage:self.resizeImage toWidth:320.0f andHeight:480.0f];
newPageView = [[UIImageView alloc] initWithImage:theImage];
newPageView.contentMode = UIViewContentModeScaleAspectFit;
newPageView.frame = frame;
[self.scrollView addSubview:newPageView];
[self.pageViews replaceObjectAtIndex:page withObject:newPageView];
}
}
- (UIImage *)resizeImage:(UIImage *)image toWidth:(float)width andHeight:(float)height {
CGSize newSize = CGSizeMake(width, height);
CGRect newRectangle = CGRectMake(0, 0, width, height);
UIGraphicsBeginImageContext(newSize);
[self.resizeImage drawInRect:newRectangle];
UIImage *resizedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return resizedImage;
}
This seems to be holding the memory at a stable place with no permanent increase in memory consumption. I am not sure if this is the best way to solve this problem so if anyone has any better ideas, please provide help.
Can anybody help me with the sample code for embedding a zoomable scroll view within a paging scroll view so that each page can be zoomed and panned individually?
Also the navigation structure is like tab bar controller --> navigation controller with buttons (on push of the buttons) --> view controller where in the horizontal scrollview of images has to be implemented with pagination and zooming.
Here is the link to the tutorial that I followed: How To Use UIScrollView to Scroll and Zoom Content
The code I've implemented is following:
#import "ViewCorpBrochureController.h"
#interface ViewCorpBrochureController ()
#property (nonatomic, strong) NSArray *pageImages;
#property (nonatomic, strong) NSMutableArray *pageViews;
#property (nonatomic, strong) UIImageView *imageView;
- (void)loadVisiblePages;
- (void)loadPage:(NSInteger)page;
- (void)purgePage:(NSInteger)page;
- (void)centerScrollViewContents;
- (void)scrollViewDoubleTapped:(UITapGestureRecognizer*)recognizer;
- (void)scrollViewTwoFingerTapped:(UITapGestureRecognizer*)recognizer;
#end
#implementation ViewCorpBrochureController
#synthesize scrollView = _scrollView;
#synthesize pageControl = _pageControl;
#synthesize pageImages = _pageImages;
#synthesize pageViews = _pageViews;
#synthesize imageView = _imageview;
- (void)centerScrollViewContents {
CGSize boundsSize = self.scrollView.bounds.size;
CGRect contentsFrame = self.imageView.frame;
if (contentsFrame.size.width < boundsSize.width) {
contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width) / 2.0f;
} else {
contentsFrame.origin.x = 0.0f;
}
if (contentsFrame.size.height < boundsSize.height) {
contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height) / 2.0f;
} else {
contentsFrame.origin.y = 0.0f;
}
self.imageView.frame = contentsFrame;
}
- (void)scrollViewDoubleTapped:(UITapGestureRecognizer*)recognizer {
// Get the location within the image view where we tapped
CGPoint pointInView = [recognizer locationInView:self.imageView];
// Get a zoom scale that's zoomed in slightly, capped at the maximum zoom scale specified by the scroll view
CGFloat newZoomScale = self.scrollView.zoomScale * 1.5f;
newZoomScale = MIN(newZoomScale, self.scrollView.maximumZoomScale);
// Figure out the rect we want to zoom to, then zoom to it
CGSize scrollViewSize = self.scrollView.bounds.size;
CGFloat w = scrollViewSize.width / newZoomScale;
CGFloat h = scrollViewSize.height / newZoomScale;
CGFloat x = pointInView.x - (w / 2.0f);
CGFloat y = pointInView.y - (h / 2.0f);
CGRect rectToZoomTo = CGRectMake(x, y, w, h);
[self.scrollView zoomToRect:rectToZoomTo animated:YES];
}
- (void)scrollViewTwoFingerTapped:(UITapGestureRecognizer*)recognizer {
// Zoom out slightly, capping at the minimum zoom scale specified by the scroll view
CGFloat newZoomScale = self.scrollView.zoomScale / 1.5f;
newZoomScale = MAX(newZoomScale, self.scrollView.minimumZoomScale);
[self.scrollView setZoomScale:newZoomScale animated:YES];
}
#pragma mark -
- (void)loadVisiblePages {
// First, determine which page is currently visible
CGFloat pageWidth = self.scrollView.frame.size.width;
NSInteger page = (NSInteger)floor((self.scrollView.contentOffset.x * 2.0f + pageWidth) / (pageWidth * 2.0f));
// Update the page control
self.pageControl.currentPage = page;
// Work out which pages we want to load
NSInteger firstPage = page - 1;
NSInteger lastPage = page + 1;
// Purge anything before the first page
for (NSInteger i=0; i<firstPage; i++) {
[self purgePage:i];
}
for (NSInteger i=firstPage; i<=lastPage; i++) {
[self loadPage:i];
}
for (NSInteger i=lastPage+1; i<self.pageImages.count; i++) {
[self purgePage:i];
}
}
- (void)loadPage:(NSInteger)page {
if (page < 0 || page >= self.pageImages.count) {
// If it's outside the range of what we have to display, then do nothing
return;
}
// Load an individual page, first seeing if we've already loaded it
UIView *pageView = [self.pageViews objectAtIndex:page];
if ((NSNull*)pageView == [NSNull null]) {
CGRect frame = self.scrollView.bounds;
frame.origin.x = frame.size.width * page;
frame.origin.y = 0.0f;
UIImageView *newPageView = [[UIImageView alloc] initWithImage:[self.pageImages objectAtIndex:page]];
newPageView.contentMode = UIViewContentModeScaleAspectFit;
newPageView.frame = frame;
[self.scrollView addSubview:newPageView];
[self.pageViews replaceObjectAtIndex:page withObject:newPageView];
}
}
- (void)purgePage:(NSInteger)page {
if (page < 0 || page >= self.pageImages.count) {
// If it's outside the range of what we have to display, then do nothing
return;
}
// Remove a page from the scroll view and reset the container array
UIView *pageView = [self.pageViews objectAtIndex:page];
if ((NSNull*)pageView != [NSNull null]) {
[pageView removeFromSuperview];
[self.pageViews replaceObjectAtIndex:page withObject:[NSNull null]];
}
}
#pragma mark -
- (void)viewDidLoad {
[super viewDidLoad];
self.title = #"CorporateBrochure";
self.pageImages = [NSArray arrayWithObjects:
[UIImage imageNamed:#"CB1.jpg"],
[UIImage imageNamed:#"CB2.jpg"],
[UIImage imageNamed:#"CB3.jpg"],
[UIImage imageNamed:#"CB4.jpg"],
[UIImage imageNamed:#"CB5.jpg"],
[UIImage imageNamed:#"CB6.jpg"],
nil];
NSInteger pageCount = self.pageImages.count;
// Set up the page control
self.pageControl.currentPage = 0;
self.pageControl.numberOfPages = pageCount;
// Set up the array to hold the views for each page
self.pageViews = [[NSMutableArray alloc] init];
for (NSInteger i = 0; i < pageCount; ++i) {
[self.pageViews addObject:[NSNull null]];
}
/* If I use this the subview appears below the image
UIImage *image = self.imageView.image;
//UIImage *image = [UIImage imageNamed:#"CB2.jpg"];
self.imageView = [[UIImageView alloc] initWithImage:image];
self.imageView.frame = (CGRect){.origin=CGPointMake(0.0f, 0.0f), .size=image.size};
[self.scrollView addSubview:self.imageView];
self.scrollView.contentSize = image.size;
*/
UITapGestureRecognizer *doubleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(scrollViewDoubleTapped:)];
doubleTapRecognizer.numberOfTapsRequired = 2;
doubleTapRecognizer.numberOfTouchesRequired = 1;
[self.scrollView addGestureRecognizer:doubleTapRecognizer];
UITapGestureRecognizer *twoFingerTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(scrollViewTwoFingerTapped:)];
twoFingerTapRecognizer.numberOfTapsRequired = 1;
twoFingerTapRecognizer.numberOfTouchesRequired = 2;
[self.scrollView addGestureRecognizer:twoFingerTapRecognizer];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
CGSize pagesScrollViewSize = self.scrollView.frame.size;
self.scrollView.contentSize = CGSizeMake(pagesScrollViewSize.width * self.pageImages.count, pagesScrollViewSize.height);
[self loadVisiblePages];
}
- (void)viewDidUnload {
[super viewDidUnload];
self.scrollView = nil;
self.pageControl = nil;
self.pageImages = nil;
self.pageViews = nil;
}
- (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView {
// Return the view that we want to zoom
return self.imageView;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return (interfaceOrientation == UIInterfaceOrientationMaskAll);
}
#pragma mark - UIScrollViewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
// Load the pages which are now on screen
[self loadVisiblePages];
}
- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
// The scroll view has zoomed, so you need to re-center the contents
[self centerScrollViewContents];
}
#end
Is there a specific issue you are having with Ray Wenderlich's tutorial?
Apple's documentation has a very good example of how to implement a paging scroll view, see the Photo Scroller sample code here. I would suggest starting there.
From the above link:
"PhotoScroller" demonstrates the use of embedded UIScrollViews and
CATiledLayer to create a rich user experience for displaying and
paginating photos that can be individually panned and zoomed.
Note: If your images are not overly large, you can get away with not using CATiledLayer.
EDIT 1: See my answer to this question about how to modify Apple's Photo Scroller code to make the UIPageViewController a subview of your own view controller (and not the rootViewController).
EDIT 2: See this sample project on github.
I'm working on a UIScrollView in iPad. The Scroll view scrolls smoothly in iOS 5.0 ,but the animation of scrolling is not smoother in Versions below 5.0.
Is there any specific customization be done to handle this?Should I add some more functionality to run UIScrollView in iOS 4.x?
-- I am facing this problem when adding custom UIView into the UIScrollView.
Working Code :
{
timeLineScrollView.frame = CGRectMake(0, 0, 500, 500);
float posX = 0;
for(int i = 0;i < 10;i++)
{
UIView *samView = [[UIView alloc]initWithFrame:CGRectMake(posX, 10, 500, 300)];
posX = posX + 500;
[timeLineScrollView addSubview:samView];
}
timeLineScrollView.contentSize = CGSizeMake(500*10, timeLineScrollView.frame.size.height);
}
Not Working Code :
{
timeLineScrollView.frame = CGRectMake(0, 0, 500, 500);
float posX = 0;
for(int i = 0;i < 10;i++)
{
CustomView *samView = [[CustomView alloc]initWithFrame:CGRectMake(posX, 10, 500, 300)];
posX = posX + 500;
[timeLineScrollView addSubview:samView];
}
timeLineScrollView.contentSize = CGSizeMake(500*10, timeLineScrollView.frame.size.height);
}
The Custom View :
- (id)initWithFrame:(CGRect)frame withEvent:(VisitHistoryEvent*)eventDetails
{
self = [super initWithFrame:frame];
if (self) {
complaint = [[UILabel alloc]init];
}
return self;
}
-(void)layoutSubviews
{
complaint.frame = CGRectMake(0, 0, 100, 20);
[self addSubview:complaint];
}
Just a hunch... If you tried to create one UIView as a subview for the UIScrollView (with a width of 3000 to match your content) and added your UILabels to that view rather than directly to the UIScrollView, perhaps then iOS will be able to cache it and give you better perf.