So I have UIScrollView. I download img from web server and add subview to uiscrollview. I'm doing this asynchronious. It downloads pictures very well but it just doesn't display them. I need to tap on the screen and move a little bit and after that the pictures appears... Is it a way do display them by the code? thanks
myWidth = [[UIScreen mainScreen] bounds].size.width;
customBtnWidth = myWidth - 30;
NSData * imageData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString: pictureUrl]];
UIImage *img = [[UIImage alloc]initWithData:imageData];
UIImageView *imgView = [[UIImageView alloc] initWithImage:img];
imgView.frame = CGRectMake( x*customBtnWidth, self.videoView.bounds.size.height ,customBtnWidth,customBtnWidth);
imgView.center = CGPointMake(15+ customBtnWidth /2 + x * customBtnWidth + x*30, customBtnWidth / 2);
[self.scrollView addSubview:imgView];
//
//[self.scrollView motionBegan:UIEventSubtypeNone withEvent:UIEventSubtypeNone];
scrollView.contentSize = CGSizeMake(self.photosView.bounds.size.width+ number*customBtnWidth, customBtnWidth );
//[self.scrollView setNeedsDisplay];
//[self.scrollView bringSubviewToFront:imgView];
[imageData release];
[img release];
[imgView release];
I see that you have already tried [self.scrollView setNeedsDisplay]; but its commented out. Did that not work?
You can also try setting scrollView's contentMode to UIViewContentModeRedraw like self.scrollView.contentMode = UIViewContentModeRedraw; while initializing the scrollView and check if that solves it.
Related
I am trying to add set of imageviews on a UIScrollView. My problem is that the imageviews are overlapping with each other even though I increase the x value. What's also weird is that this problem is only for devices with ios 4.2.1, but works on simulator 4.2 and other device ios.
Here is my code:
- (void)addScrollView {
[self setImages];
scrollView = [[UIScrollView alloc] initWithFrame:self.frame];
scrollView.delegate = self;
[scrollView setBackgroundColor:[UIColor blackColor]];
[scrollView setCanCancelContentTouches:NO];
scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
scrollView.clipsToBounds = YES;
scrollView.scrollEnabled = YES;
scrollView.pagingEnabled = YES;
[self addSubview:scrollView];
NSUInteger nimages;
CGFloat cx = 0;
for (nimages = 1; nimages < [imagesArray count] ; nimages++) {
UIImage *image = [UIImage imageNamed:[imagesArray objectAtIndex:nimages]];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
CGRect rect = imageView.frame;
rect.origin.x = cx;
rect.origin.y = 0;
rect.size.width = 320;
rect.size.height = 480;
imageView.frame = rect;
[scrollView addSubview:imageView];
[imageView release];
cx += rect.size.width;
}
[scrollView setContentSize:CGSizeMake(cx, [scrollView bounds].size.height)];
}
Called from here:
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
[self addScrollView];
UIImage *handImg;
UIImageView *longhand = [[UIImageView alloc] init];
minuteHand = [[UIView alloc] initWithFrame:CGRectMake(0, 55, 320, 480)];
handImg = [UIImage imageNamed:#"clock_long_hand.png"];
longhand.image = handImg;
/************** TRY COMMENT OUT HERE **************/
longhand.frame = CGRectMake(155 - (handImg.size.width / 2), 240 - handImg.size.height, handImg.size.width, handImg.size.height);
[minuteHand addSubview:longhand];
[self addSubview:minuteHand];
/************** END COMMENT OUT HERE **************/
[longhand release];
}
return self;
}
UPDATE:
This code is in a UIView subclass which is why I use [self...] instead of [self.view...].
I tried experimenting and found that when I comment out the indicated parts, the scrollview works fine. But when it is included, this is when the imageviews are overlapped.
I know that the scrollview's content size is correct because its indicator continues to scroll, with just a plain black background.
I am really confused why this works on some ios and not on others. Hope you can help.
This might have something to do with autoresizing mask. The width actual images, I mean .png files is bigger than 320, right?
I'm new in iOS. Now I want to load view images from URL to page control using scroll view. When I run the program the first image is shown but when I try to slide to next image or I move to another page program is not responding. My guess is probably related to the size of image.
The following is my code to load the image. I put this code in -(void) viewDidLOad...
CGRect screenShot = screenView.frame;
screenShot.origin.y = description.frame.origin.y + description.frame.size.height + 30;
screenView.frame = screenShot;
pageControlBeingUsed = NO;
for (int i = 0; i < [myArrayImagesURL count]; i++) {
CGRect frame;
frame.origin.x = self.scrollView.frame.size.width * i;
frame.origin.y = 0;
frame.size = self.scrollView.frame.size;
UIImageView *iv = [[[UIImageView alloc] initWithFrame:CGRectMake(scrollView.bounds.size.width * i, 0, scrollView.bounds.size.width, scrollView.bounds.size.height)] autorelease];
iv.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:
[NSURL URLWithString:[myArrayImagesURL objectAtIndex:i]]]];
[self.scrollView addSubview:iv];
[iv release];
}
self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * [myArrayImagesURL count], self.scrollView.frame.size.height);
self.pageControl.currentPage = 0;
self.pageControl.numberOfPages = [myArrayImagesURL count];
It looks like you have set the imageView to autorelease and the released it. This should be wrong. Try removing the autorelease tag when you create the imageView. It should be properly retained now.
UIImageView *iv = [[UIImageView alloc] initWithFrame:CGRectMake(scrollView.bounds.size.width * i, 0, scrollView.bounds.size.width, scrollView.bounds.size.height)];
- (void)viewDidLoad
{
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapDetected:)];
tapGesture.numberOfTapsRequired = 1;
tapGesture.numberOfTouchesRequired = 1;
scrollView = [[UIScrollView alloc] initWithFrame:self.view.frame];
int numberOfImages = 32;
CGFloat currentX = 0.0f;
for (int i=1; i <= numberOfImages; i++) {
// create image
NSString *imageName = [NSString stringWithFormat:#"page-%d.jpg", i];
UIImage *image = [UIImage imageNamed:imageName];
imageView = [[UIImageView alloc] initWithImage:image];
// put image on correct position
CGRect rect = imageView.frame;
rect.origin.x = currentX;
imageView.frame = rect;
// update currentX
currentX +=454; //mageView.frame.size.width;
[scrollView addSubview:imageView];
[imageView release];
}
[scrollView addGestureRecognizer:tapGesture];
scrollView.contentSize = CGSizeMake(currentX, 800);
scrollView.pagingEnabled=YES;
scrollView.userInteractionEnabled = YES;
scrollView.maximumZoomScale = 15;
scrollView.minimumZoomScale = 0.5;
scrollView.bounces = NO;
scrollView.bouncesZoom = NO;
scrollView.delegate = self;
scrollView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin;
[self.view addSubview:scrollView];
[scrollView release];
[super viewDidLoad];
}
}
in above code when i apply zoom or tap event with a single image then it work for that. But when same event apply for array of image then not working. why is it happened?
Its quiet complex to implement zoom in this kind of image flow. Anyway i wil suggest you one idea,
Add the gesture to each imageView. In the method, add a new scrollview, with the respective imageView.. then implement zoom.
EDIT:
In the tapgesture method,
1.Find out the which imageView is visible at that time.
2.Then create a new scrollview,with that single imageview.
3.Implement zoom functionality in that new scrollview.
4.During zoom out,If the new scrollview size is equal to the actual value,remove the new scrollview fro the super view so that the array of images is visible.
Simplest way is create a big wrapper view first, and insert it into ScrollView.
And then add all your imageViews to the wrapper view.
I'm not sure I did understand that very well in the Apple doc. I'm considering using CATiledLayer to display a JPEG image. However, I only have an entire JPEG file at my disposal and no small tiles. Is it still possible to use a CATiledLayer and let it "tile" the JPEG?
Thanks!
No. You will have to tile them yourself, unfortunately. The WWDC 2010 videos on Core Animation discuss how to do this and in their sample code, they demonstrate how to use a CATileLayer when the tiles already exist.
Correction
I meant to say watch the Scroll View session. It's session 104 "Designing Apps with Scroll Views"
You may use This for making CATileLayer with image and Zoom functionality in scrollview.
- (void)viewDidLoad
{
[super viewDidLoad];
// You do not need to and must not autorelease [NSBundle mainBundle]
NSString *path = [[NSBundle mainBundle] pathForResource:#"img" ofType:#"jpg"];
NSData *data = [NSData dataWithContentsOfFile:path];
image = [UIImage imageWithData:data];
// CGRect pageRect = CGRectMake(0, 0, 1600, 2400);
CGRect pageRect = CGRectMake(0.0, 0.0, image.size.width, image.size.height);
CATiledLayer *tiledLayer = [CATiledLayer layer];
tiledLayer.delegate = self;
tiledLayer.tileSize = CGSizeMake(256.0, 256.0);
tiledLayer.levelsOfDetail = 5; // was 1000, which makes no sense. Each level of detail is a power of 2.
tiledLayer.levelsOfDetailBias = 5; // was 1000, which also makes no sense.
// Do not change the tiledLayer.frame.
tiledLayer.bounds = pageRect; // I think you meant bounds instead of frame.
// Flip the image vertically.
tiledLayer.transform = CATransform3DMakeScale(1.0f, -1.0F, 1.0f);
myContentView = [[UIView alloc] initWithFrame:CGRectMake(500,400,image.size.width,image.size.height)];
[myContentView.layer addSublayer:tiledLayer];
// UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:self.view.bounds];
scrollView=[[UIScrollView alloc]initWithFrame:CGRectMake(10, 10, 300, 400)];
scrollView.backgroundColor = [UIColor whiteColor];
// [scrollView setContentSize:CGSizeMake(image.size.width,image.size.height)];
[scrollView setContentSize:image.size];
scrollView.maximumZoomScale = 32; // = 2 ^ 5
scrollView.delegate = self;
// scrollView.contentSize = pageRect.size;
[scrollView addSubview:myContentView];
[self.view addSubview:scrollView];
}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return myContentView;
}
- (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)context
{
NSString *path = [[NSBundle mainBundle] pathForResource:#"img" ofType:#"jpg"];
NSData *data = [NSData dataWithContentsOfFile:path];
image = [UIImage imageWithData:data];
CGRect imageRect = CGRectMake (0.0, 0.0, image.size.width, image.size.height);
CGContextDrawImage (context, imageRect, [image CGImage]);
}
The easier way is to just downscale the image until it fits (I think devices support up to 2044x2044 or so). You can create subimages of a CGImage with CGImageCreateWithImageInRect()
I've been struggling with trying to get my UIImageView to change its image when the UIScrollView is scrolled, kind of like the Photos.app.
Here's my code:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
if (scrollView.contentOffset.x > 296){
self.currentDBNum++;
self.currentDoorbell = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:[[self.doorbells objectAtIndex:currentDBNum] objectForKey:#"Image"] ofType:#"jpg"]];
self.doorbellPic.image = currentDoorbell;
self.currentSoundPath = [[NSBundle mainBundle] pathForResource:[[doorbells objectAtIndex:currentDBNum] objectForKey:#"Sound"] ofType:#"caf"];
}
}
Any hints? Thanks. (The images have a width of 296.)
There are two ways that accomplish your task:
Try to learn Three20 TTPhotoViewController that will do exactly the same as the photo.app that you see in your iphone.
If you want to do it yourself then from my experience, you have to add multiple UIImageView with the correct position (x,y,width,height) to the UIScrollView. Remember to initialize the scroll view with the right content-size so that it's scrollable. An example: image1 is (0,0,320,480), image2 is (320,0,320,480), image3 is (640,0,320,480), etc... then your scroll view content size will be the x's value of the last item + the width of the last item.
Antohny,
I do not have my own source code right with me, but I can suggest you the following link:
http://github.com/andreyvit/ScrollingMadness
I think it will give you an idea so you can implement it without hitting the corners.
you can do it by using following code:
UIImageView *tempImageView ;
int initialXPos = 0;
int initialYPos = 30;
view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 800)];
int arraycounter=0;
for (int i=0; i<numrows; i++)
{
for (int j=0; j<numImagesPerColumn; j++)
{
NSURL *url=[NSURL URLWithString:[aPhoto.childphotos objectAtIndex:arraycounter]];
UIImage *image1;
CGRect image1Frame;
image1 = [UIImage imageWithData:[NSData dataWithContentsOfURL:url]];
image1Frame = CGRectMake(initialXPos,initialYPos, 80, 80);
tempImageView = [[UIImageView alloc] initWithFrame:image1Frame];
tempImageView.image=image1;
tempImageView.tag = 0;
initialXPos = initialXPos + 80 + 4;
[view addSubview:tempImageView];
arraycounter=arraycounter+1;
}
initialXPos=0;
initialYPos = initialYPos + 86;
}
scrollView.maximumZoomScale = 4.0;
scrollView.minimumZoomScale = 0.75;
scrollView.clipsToBounds = YES;
scrollView.delegate = self;
[scrollView addSubview:view];
[scrollView addSubview:title];
[scrollView addSubview:des];
[self.view addSubview:scrollView ];
u try this
-(void)getButtonRowSize:(int)_rowsize Count:(int)_count
{
[scrollView setFrame:CGRectMake(0, 0, 320, 480)];
[scrollView setContentSize:CGSizeMake(320,((320-_rowsize*IMAGEGAP)/_rowsize)*(_count/_rowsize +1)+(_count/_rowsize)*IMAGEGAP)];
for(int i=0;i<_count;i++)
{
[scrollView addSubview:[self getButtonRowSize:_rowsize Count:_count currentPos:i]];
}
}
-(UIButton *)getButtonRowSize:(int)_rowsize Count:(int)_count currentPos:(int)_pos
{
UIButton *button=[UIButton buttonWithType:UIButtonTypeCustom];
[button setFrame:CGRectMake((_pos%_rowsize)*((320-(_rowsize+1)*IMAGEGAP)/_rowsize)+(_pos%_rowsize +1)*IMAGEGAP,(_pos/_rowsize)*((320-(_rowsize+1)*IMAGEGAP)/_rowsize)+(_pos/_rowsize +1)*IMAGEGAP,((320-(_rowsize+1)*IMAGEGAP)/_rowsize),((320-(_rowsize+1)*IMAGEGAP)/_rowsize))];
[button setBackgroundImage:[self resizingImagewithimagename:[UIImage imageNamed:#"add image file name"] Length:((320-(_rowsize+1)*IMAGEGAP)/_rowsize)] forState:UIControlStateNormal];
return button;
}