I have different images for portrait and landscape, I fetch the images from the Document directory, their is a total of 62 images. 31 Landscape images having 1015x745 dimensions and 31 Portrait having 751x1024 dimensions. All the images loading on the simulator but when i run the same code within the device the application crash. It load either only the portrait on landscape images.
int porWidth = 768, lanWidth = 1024;
int i=0;
for (CatalogIndividuals *cat in self.array)
{
UIImageView *imageView1 = [[[UIImageView alloc] initWithFrame:CGRectMake(porWidth*i +5, 0, 757, 964)] autorelease];
imageView1.tag = porImage+i;
NSString *fullPath =[self.documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"%#",cat.portraitImage]];
imageView1.image = [UIImage imageWithData:[NSData dataWithContentsOfFile:[fullPath stringByReplacingOccurrencesOfString:#"\\" withString:#"/"]]];
imageView1.contentMode = UIViewContentModeScaleAspectFit;
UIImageView *imageView2 = [[[UIImageView alloc] initWithFrame:CGRectMake(lanWidth*i +5, 0, 1015, 620)] autorelease];
imageView2.tag = lanImage+i;
NSString *tempPath = [self.documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"%#",cat.landscapImage]];
NSString *str = [tempPath stringByReplacingOccurrencesOfString:#"\\" withString:#"/"];
NSLog(#"imageView1 fullPath = %#",str);
imageView2.image = [UIImage imageWithData:[NSData dataWithContentsOfFile:str]];}
I think there is some memory leak problem. please help if anybody has any solution.
That's about 350MB worth of images. You don't have a memory leak, you're just using far too much memory. This is a mobile device, not a desktop computer, the resources available to you are limited.
You shouldn't be loading all the images at once, you should be loading them dynamically as you scroll through the content. Take a look at the sample code Apple provides for UIScrollView to see how you can use tiling to achieve this.
Related
The code to render a MKMapView to an UIImage no longer works in iOS 7. It returns an empty image with nothing but the word "Legal" at the bottom and a black compass on the top right. The map itself is missing. Below is my code:
UIGraphicsBeginImageContext(map.bounds.size);
[map.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Map is an IBOutlet that points to a MKMapView. Is there any way to render a MKMapView correctly in iOS 7?
From this SO post:
You can use MKMapSnapshotter and grab the image from the resulting MKMapSnapshot. See the discussion of it WWDC 2013 session video, Putting Map Kit in Perspective.
For example:
MKMapSnapshotOptions *options = [[MKMapSnapshotOptions alloc] init];
options.region = self.mapView.region;
options.scale = [UIScreen mainScreen].scale;
options.size = self.mapView.frame.size;
MKMapSnapshotter *snapshotter = [[MKMapSnapshotter alloc] initWithOptions:options];
[snapshotter startWithCompletionHandler:^(MKMapSnapshot *snapshot, NSError *error) {
UIImage *image = snapshot.image;
NSData *data = UIImagePNGRepresentation(image);
[data writeToFile:[self snapshotFilename] atomically:YES];
}];
Having said that, the renderInContext solution still works for me. There are notes about only doing that in the main queue in iOS7, but it still seems to work. But MKMapSnapshotter seems like the more appropriate solution for iOS7.
So I have this UIImageView with an image on top of it. When I'm using normal iPhone display, it shows inside the UIImageView exactly as it supposed to - in the UIImageView bounds, the problem is when I'm using retina display device, the image becomes big and doesn't fit the UIImageView bounds, it goes all over the screen.
How can I fix this issue? I want the image in Retina display to fit inside the UIImageView size.
This is my code:
- (UIImage *)loadScreenShotImageFromDocumentsDirectory
{
UIImage * tempimage;
NSArray *sysPaths = NSSearchPathForDirectoriesInDomains( NSDocumentDirectory, NSUserDomainMask, YES );
NSString *docDirectory = [sysPaths objectAtIndex:0];
NSString *filePath = [NSString stringWithFormat:#"%#/MeasureScreenShot.png", docDirectory];
tempimage = [[UIImage alloc] initWithContentsOfFile:filePath];
return tempimage;
}
- (void)viewDidLoad
{
// Setting the image
UIImage * Image = [self loadScreenShotImageFromDocumentsDirectory];
theImageView.frame = CGRectMake(0, 166, 290, 334);
theImageView.contentMode = UIViewContentModeCenter;
theImageView.image = Image;
}
Thank in advance!
Try setting the content mode to UIViewContentModeScaleAspectFit
When I was using an image with core plot, I had to scale the image for the retina display.
CPTImage *fillimage = [CPTImage imageWithCGImage:bubble.CGImage scale:bubble.scale];
the name of the image file was bubble and I had a bubble file and a bubble#2x file. This let the image fit the image view for either display. Hope this helps.
I have scenario, in which I am getting images using Web Service and all images are in different resolution. Now my requirement is that I want resolution of each Images and using that I want to define size of UIImageView so I can prevent my Images from getting blurred
For example image resolution if 326 pixel/inch the imageview should be as size of that image can represent fully without any blur.
UIImage *img = [UIImage imageNamed:#"foo.png"];
CGRect rect = CGRectMake(0, 0, img.size.width, img.size.height);
UIImageView *imgView = [[UIImageView alloc] initWithFrame:rect];
[imgView setImage:img];
Image size IS it's resolution.
Your problem might be - retina display!
Check for Retina display and thus - make UIImageView width/height twice smaller (so that each UIImageView pixel would consist of four smaller UIImage pixels for retina display).
How to check for retina display:
https://stackoverflow.com/a/7607087/894671
How to check image size (without actually loading image in memory):
NSString *mFullPath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject]
stringByAppendingPathComponent:#"imageName.png"];
NSURL *imageFileURL = [NSURL fileURLWithPath:mFullPath];
CGImageSourceRef imageSource = CGImageSourceCreateWithURL((CFURLRef)imageFileURL, NULL);
if (imageSource == NULL)
{
// Error loading image ...
}
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithBool:NO], (NSString *)kCGImageSourceShouldCache, nil];
CFDictionaryRef imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, (CFDictionaryRef)options);
NSNumber *mImgWidth;
NSNumber *mImgHeight;
if (imageProperties)
{
//loaded image width
mImgWidth = (NSNumber *)CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelWidth);
//loaded image height
mImgHeight = (NSNumber *)CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelHeight);
CFRelease(imageProperties);
}
if (imageSource != NULL)
{
CFRelease(imageSource);
}
So - for example:
UIImageView *mImgView = [[UIImageView alloc] init];
[mImgView setImage:[UIImage imageNamed:#"imageName.png"]];
[[self view] addSubview:mImgView];
if ([UIScreen instancesRespondToSelector:#selector(scale)])
{
CGFloat scale = [[UIScreen mainScreen] scale];
if (scale > 1.0)
{
//iphone retina screen
[mImgView setFrame:CGRectMake(0,0,[mImgWidth intValue]/2,[mImgHeight intValue]/2)];
}
else
{
//iphone screen
[mImgView setFrame:CGRectMake(0,0,[mImgWidth intValue],[mImgHeight intValue])];
}
}
Hope that helps!
You can get image size using following code. So, first calculate downloaded image size and than make image view according to that.
UIImage *Yourimage = [UIImage imageNamed:#"image.png"];
CGFloat width = Yourimage.size.width;
CGFloat height = Yourimage.size.height;
Hope, this will help you..
UIImage *oldimage = [UIImage imageWithContentsOfFile:imagePath]; // or you can set from url with NSURL
CGSize imgSize = [oldimage size];
imgview.frame = CGRectMake(10, 10, imgSize.width,imgSize.height);
[imgview setImage:oldimage];
100% working ....
To solve this problem, we need to take care of the device's display resolution..
For example you have an image of resolution 326ppi which is same as of iPhone4, iPhone4S and iPod 4th Gen. So you can simply use solutions suggested by #Nit and #Peko. But for other devices(or for image with different resolution on these devices) you will need to apply maths to calculate size for better display.
Now suppose you have 260ppi(with dimensions W x H) image and you wish to display it on iPhone4S, so as the information contained in it per inches is less than the display resolution of iPhone so we will need to resize it by reducing image size by 326/260 factor. so now the size for imageView that you will use is
imageViewWidth = W*(260/326);
imageViewHeight = H*(260/326);
In general:
resizeFactor = imageResolution/deviceDisplayResolution;
imageViewWidth = W*resizeFactor;
imageViewHeight = H*resizeFactor;
Here I am considering when we set an image in imageView and resize it, it does not removes or adds pixels from image,
Let the UIImageView do the work by utilizing the contentMode property to do your image resizing for you.
You probably want to be displaying your UIImageView with a static sizing (the "frame" property) that represents the maximum size of the image you want to display, and allowing the images to resize within that frame relative to their own particular size requirements (overall size, aspect ratio, etc.). You can let the UIImageView do the heavy lifting for you of dealing with different sized images by mastering the contentMode property. It has many different settings, one of which is UIViewContentModeScaleAspectFit, which will downsize your image as necessary to fit within the UIImageView, which if the image is smaller, it will simply display centered. You can play with the setting to get the results you want.
Note that with this approach, there is nothing special you need to do to deal with scaling issues associated with a Retina display.
As per the requirement you stated in the question body, I believe you need not change UIImageView size.
Image can represent fully without any blur using this line of code:
imageView.contentMode = UIViewContentModeScaleAspectFit;
I have an animated image which works great. It consists of 180 high quality images and it plays fine and loops continuously. My problem is that the first time I load the view containing these images it takes a long time to load. Every subsequent time after that it loads immediately as I am assuming that the images have been cached or preloaded!!! I come from a flash background and as I am sure you aware preloaders are as common as muck so I don't feel this should be difficult to find but after countless googling I cannot find any good examples on preloading or any articles on why there is a delay and what to do about it.
So my question(s) is this:
Is there a checkbox in the info.plist to preload all my images at the start of the app?
How can you preload images and are there any simple example projects that I could look at?
Is this the best way to implement what is essentially a video but has been output to a png sequence?
Is there another method as viewDidLoad does not work as I expect it to do. It traces "FINISHED LOADING IMAGES" (see code below) but the view does not show for a second or two after the images have been loaded so if the view does not show until the images have loaded then neither will the UIActivityIndicatorView which is also in the same view.
How do you do event listening in objective c?
Below is the code in the viewDidLoad which I believe is fairly standard:
Any help is greatly appreciated as I am banging my head on a brick wall on something that seems so basic in ui development. Help :)
- (void)viewDidLoad {
[super viewDidLoad];
imageArray = [[NSMutableArray alloc] initWithCapacity:IMAGE_COUNT];
NSLog(#"START LOADING IMAGES");
// Build array of images, cycling through image names
for (int i = 0; i < IMAGE_COUNT; i++){
[imageArray addObject:[UIImage imageNamed: [NSString stringWithFormat:#"Main_%d.png", i]]];
}
animatedImages = [[UIImageView alloc] initWithFrame:CGRectMake(0,20,IMAGE_WIDTH, IMAGE_HEIGHT)];
animatedImages.animationImages = [NSArray arrayWithArray:imageArray];
animatedImages.animationDuration = 6.0;
animatedImages.animationRepeatCount = 0;
[self.view addSubview:animatedImages];
animatedImages.startAnimating;
[animatedImages release];
NSLog(#"FINISH LOADING IMAGES");
}
Cheers
M
In case someone finds this question, I have an answer, which is to pre-render the images like this.
NSMutableArray *menuanimationImages = [[NSMutableArray alloc] init];
for (int aniCount = 1; aniCount < 21; aniCount++) {
NSString *fileLocation = [[NSBundle mainBundle] pathForResource: [NSString stringWithFormat: #"bg%i", aniCount + 1] ofType: #"png"];
// here is the code to load and pre-render the image
UIImage *frameImage = [UIImage imageWithContentsOfFile: fileLocation];
UIGraphicsBeginImageContext(frameImage.size);
CGRect rect = CGRectMake(0, 0, frameImage.size.width, frameImage.size.height);
[frameImage drawInRect:rect];
UIImage *renderedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// then add the resulting image to the array
[menuanimationImages addObject:renderedImage];
}
settingsBackground.animationImages = menuanimationImages;
I have tried multiple other methods of pre-loading images, and this is the only thing I've found that works.
My problem is that the first time I load the view containing these images it takes a long time to load. Every subsequent time after that it loads immediately as I am assuming that the images have been cached or preloaded
you are right at this point ...... as you are using method imageNamed: for this method document quotes.....
This method looks in the system caches for an image object with the specified name and returns that object if it exists. If a matching image object is not already in the cache, this method loads the image data from the specified file, caches it, and then returns the resulting object.
so in my opinion, rather than doing following stuff in viewDidLoad, you should do it earlier where delay is of not considerable......
for (int i = 0; i < IMAGE_COUNT; i++)
{
[imageArray addObject:[UIImage imageNamed: [NSString stringWithFormat:#"Main_%d.png", i]]];
}
another approach
- (void)spinLayer:(CALayer *)inLayer duration:(CFTimeInterval)inDuration
direction:(int)direction
{
CABasicAnimation* rotationAnimation;
// Rotate about the z axis
rotationAnimation =
[CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
// Rotate 360 degress, in direction specified
rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 2.0 * direction];
// Perform the rotation over this many seconds
rotationAnimation.duration = inDuration;
rotationAnimation.repeatCount = 100;
//rotationAnimation.
// Set the pacing of the animation
//rotationAnimation.timingFunction =
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
// Add animation to the layer and make it so
[inLayer addAnimation:rotationAnimation forKey:#"rotationAnimation"];
}
this method will help in animation call it as follow(I am assuming that you are putting above method in same class where you have imageView.
[self spinLayer:yourImageView.layer duration:5.0
direction:<-1 or 1 for anti clockwise or clockwise spin>];
remember just set only one image to that imageView(which you wish to animate.
thanks,
I'm trying to add more than 10 pictures on ScrollView.
NSUInteger i;
for (i = 1; i <= numberOfImage; i++)
{
NSString *imageName = [NSString stringWithFormat:#"d%dimage%d.png", imageSection, i];
UIImage *image = [UIImage imageNamed:imageName];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
// setup each frame to a default height and width, it will be properly placed when we call "updateScrollList"
CGRect rect = imageView.frame;
rect.size.height = kScrollObjHeight;
rect.size.width = kScrollObjWidth;
imageView.frame = rect;
imageView.tag = i; // tag our images for later use when we place them in serial fashion
[scrollView addSubview:imageView];
[imageView release];
}
This code is from Apple example and it works fine. But if the variable 'i' is bigger than 10, 'UIImage *image' is empty. The imageName seems to correct. But I don't know why it does not load image. Does anybody sees the problem??
And one more thing. If I do like that, does iOS controls memory automatically? I mean it's kind of wasting memory if all (more than 10) images are loaded on memory even they are not displayed. I've heard that iOS loads images only displayed on screen and free images those are not displayed. Is that right?
Thanks for reading.
UIimage imageNamed: does cache file contents. I recommend you to use UIImage +imageWithContentsOfFile: that doesn't cache at all in such situation.
You have to make sure the images have the correct name (like 0dimage11.jpg) and are added to the XCode project.
You probably have to set the contentSize accordingly.
IOS will not do that magic memory management thing unless you are using a CATiledLayer based UIView.
If UIImage is not created, it because the name does not refer to an image in the resource folder and you should have an exception.
You need to have the correct file names. You said you think the file names are correct.
NSLog(#"Loop %d: d%dimage%d.png", i,imageSection, i]);
Log out the file names so you can see what the names actually are. Place that line in your loop.
NSUInteger i;
for (i = 1; i <= numberOfImage; i++)
{
NSString *imageName = [NSString stringWithFormat:#"d%dimage%d.png", imageSection, i];
NSLog(#"Loop %d: d%dimage%d.png", i,imageSection, i]);
UIImage *image = [UIImage imageNamed:imageName];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
// setup each frame to a default height and width, it will be properly placed when we call "updateScrollList"
CGRect rect = imageView.frame;
rect.size.height = kScrollObjHeight;
rect.size.width = kScrollObjWidth;
imageView.frame = rect;
imageView.tag = i; // tag our images for later use when we place them in serial fashion
[scrollView addSubview:imageView];
[imageView release];
}
Then monitor the filenames in the debugger and see if those image files exist, and in the same directory where Apple put their image files.
Hey,Its not good way to load 10 images at once.All things you have done correct and still you'r image display empty then please check log may be there is memory warning.You can you apple's sample code photoscroller. It will do all thing that you want and also manages good memory.there are two method one is using CATieldLayer and another one directly load images. I recommended you to use method that uses CATieldLayer.
Sorry guys. This is turned out to be my fault. well, not exactly MY fault. Designers throw me many files with wrong filenames like d1imgae11.png... Anyway tips from all you guys gave me different view to see the problem and I got another hint about not to cache images. Thanks.