I am using the ImageDemo template and it works great if I code in an image from the bundle but when I try and load them from directories I have created in my app I have no luck.
Code:
- (AQGridViewCell *) gridView: (AQGridView *) aGridView cellForItemAtIndex: (NSUInteger) index
{
static NSString * PlainCellIdentifier = #"PlainCellIdentifier";
AQGridViewCell * cell = nil;
ImageDemoGridViewCell * plainCell = (ImageDemoGridViewCell *)[aGridView dequeueReusableCellWithIdentifier: PlainCellIdentifier];
if ( plainCell == nil )
{
plainCell = [[[ImageDemoGridViewCell alloc] initWithFrame: CGRectMake(0.0, 0.0, 200.0, 150.0)
reuseIdentifier: PlainCellIdentifier] autorelease];
plainCell.selectionGlowColor = [UIColor lightGrayColor];
}
NSString *fileName = [NSString stringWithFormat:#"%#/%#_tn.jpg",[manufacturerID stringValue], [[[self.collectionItems objectAtIndex:index] valueForKey:#"PhotoName"] stringByReplacingOccurrencesOfString:#" " withString:#"%20"]];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath = [paths objectAtIndex:0];
NSString *savePath =[documentsPath stringByAppendingPathComponent:fileName] ;
NSData *imageData = nil;
BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:savePath];
if (fileExists) {
imageData = [NSData dataWithContentsOfFile:savePath];
} else {
NSString *filePath = [[NSBundle mainBundle] pathForResource:#"NoImageAvailableThumbNail" ofType:#"png"];
imageData = [NSData dataWithContentsOfFile:filePath];
}
UIImage *myImage = [UIImage imageWithData:imageData];
NSLog(#"%#", myImage);
if (myImage==nil) {
NSLog(#"NO IMAGE");
}
plainCell.image = myImage;
cell = plainCell;
return ( cell );
}
I code I am using to pull the image data I know works because I use it all over in other places in my app and I am checking for nil when I set the property on the AQGridViewCell:
- (void) setImage: (UIImage *) anImage
{
_imageView.image = anImage;
[self setNeedsLayout];
}
I don't see the check for a nil UIImage in your example there. Are you certain it's being loaded correctly? Try creating the image on one line and setting it on another so you can see it being created in the debugger. For reference, I do something similar with cached book cover images in the Kobo app, and that works. One difference though is that I use the C methods to load a UIImage from a PNG file. Something like UIImageFromPNGData(), off the top of my head (sorry replying by iPhone right now).
The only other thing I can think to check is whether the image view is hidden for some reason. Printing it in the debugger should tell you that, along with it's size, layout, etc.
Related
I'm creating images array for UIImageView so I can use [_myImageView startAnimating]; method. I figuree out that if I cache(preload) it like this way the animation is fluent.
But in Instruments I see, that game is deallocated but there is still too much memory allocated - I think there are some fragments of this UIGraphicsBeginContext stuff.
Am I using it right, is there some other way how to dealloc it?
Thanks in advance!
- (NSMutableArray *)generateCachedImageArrayWithFilename:(NSString *)filename extension:(NSString *)extension andImageCount:(int)count
{
_imagesArray = [[NSMutableArray alloc] init];
_fileExtension = extension;
_animationImageName = filename;
_imageCount = count;
for (int i = 0; i < count; i++)
{
NSString *tempImageNames = [NSString stringWithFormat:#"%#%i", filename, i];
NSString *imagePath = [[NSBundle mainBundle] pathForResource:tempImageNames ofType:extension];
UIImage *frameImage = [self loadRetinaImageIfAvailable:imagePath];
UIGraphicsBeginImageContext(frameImage.size);
CGRect rect = CGRectMake(0, 0, frameImage.size.width, frameImage.size.height);
[frameImage drawInRect:rect];
UIImage *renderedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
[_imagesArray addObject:renderedImage];
if (_isDoublingFrames)
{
[_imagesArray addObject:renderedImage];
}
else if (_isTriplingFrames)
{
[_imagesArray addObject:renderedImage];
[_imagesArray addObject:renderedImage];
}
NSLog(#"filename = %#", filename);
}
return _imagesArray;
}
- (UIImage *)loadRetinaImageIfAvailable:(NSString *)path
{
NSString *retinaPath = [[path stringByDeletingLastPathComponent] stringByAppendingPathComponent:[NSString stringWithFormat:#"%##2x.%#", [[path lastPathComponent] stringByDeletingPathExtension], [path pathExtension]]];
if ([UIScreen mainScreen].scale == 2.0 && [[NSFileManager defaultManager] fileExistsAtPath:retinaPath] == YES)
return [[UIImage alloc] initWithCGImage:[[UIImage imageWithData:[NSData dataWithContentsOfFile:retinaPath]] CGImage] scale:2.0 orientation:UIImageOrientationUp];
else
return [UIImage imageWithContentsOfFile:path];
}
-(void) dealloc
{
[_imagesArray removeAllObjects];
_imagesArray = nil;
}
I had memory issues similar you wrote and what I would try out in your code
1) use #autoreleasepool
to wrap either the method or the content of the loop in #autoreleasepool { } to create a local pool which will be released after method is done. In your situation it seems to me wrapping the loop is better:
for (int i = 0; i < count; i++)
{
#autoreleasepool {
// the loop code
...
}}
2) kill [UIImage imageNamed]
Using imageNamed will prepare a cache (depending on the size of image) which will never be flushed out of the memory unless you reach a memory warning. Even if you set myImage.image = nil, the image is still in memory. XCode's Intruments tool Allocations view will show it nicely. What you can do is initialize UIImage like this, and iOS won't cache the image:
image = [UIImage imageWithContentsOfFile:fullpath];
You might use imageNamed in your code under loadRetinaImageIfAvailable.
Keep both two approach and let's check this out again!
I have a little flow problem with my UICollectionView. I want to display PDF's thumbnails just like in Apple's iBook app, when I scroll my collection view I can see it's not really smooth. Here is the way I use to load my pictures :
- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath: (NSIndexPath *)indexPath
{
GridCell *cell = [cv dequeueReusableCellWithReuseIdentifier:#"gridCell" forIndexPath:indexPath];
...
// Set Thumbnail
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
if ([Tools checkIfLocalFileExist:cell.pdfDoc])
{
UIImage *thumbnail = [Tools generateThumbnailForFile:((PDFDocument *)[self.pdfList objectAtIndex:indexPath.row]).title];
dispatch_async( dispatch_get_main_queue(), ^{
[cell.imageView setImage:thumbnail];
});
}
});
...
return cell;
}
Method to get thumbnail :
+ (UIImage *)generateThumbnailForFile:(NSString *) fileName
{
// ----- Check if thumbnail already exist
NSString* documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString* thumbnailAddress = [documentsPath stringByAppendingPathComponent:[[fileName stringByDeletingPathExtension] stringByAppendingString:#".png"]];
BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:thumbnailAddress];
if (fileExists)
return [UIImage imageWithContentsOfFile:thumbnailAddress];
// ----- Generate Thumbnail
NSString* filePath = [documentsPath stringByAppendingPathComponent:fileName];
CFURLRef url = (__bridge CFURLRef)[NSURL fileURLWithPath:filePath];
CGPDFDocumentRef documentRef = CGPDFDocumentCreateWithURL(url);
CGPDFPageRef pageRef = CGPDFDocumentGetPage(documentRef, 1);
CGRect pageRect = CGPDFPageGetBoxRect(pageRef, kCGPDFCropBox);
UIGraphicsBeginImageContext(pageRect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(context, CGRectGetMinX(pageRect),CGRectGetMaxY(pageRect));
CGContextScaleCTM(context, 1, -1);
CGContextTranslateCTM(context, -(pageRect.origin.x), -(pageRect.origin.y));
CGContextDrawPDFPage(context, pageRef);
// ----- Save Image
UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();
NSData *imageData = [NSData dataWithData:UIImagePNGRepresentation(finalImage)];
[imageData writeToFile:thumbnailAddress atomically:YES];
UIGraphicsEndImageContext();
return finalImage;
}
Do you have any suggestion ?
Take a look at https://github.com/rs/SDWebImage. The library works great for async image loading particularly the method setImageWithURL:placeholderImage:
You can call that method and set a place holder with a loading image or blank png and once the image you are trying to retrieve is loaded it will fill in the place holder. This should speed up your app quite a bit.
Hi Im really having a hard time saving in my NSDocumentDirectory.Im using AGImagePickerby the way. Yes I was able to save this in NSDocumentDirectory. But how to save them uniquely ( in terms of their own then converting their names into oneSlotImages) or save them with their unique IDs then load them back. Sorry Im kinda new to this UIImagePickerControllerMediaURL thing., I think that would be my solution to my other problem for not overlaping them when saving. How to save this using their unique ID, or UIImagePickerControllerMediaURL.
for (int i = 0; i < info.count; i++) {
NSLog(#"%#", [info objectAtIndex:i]);
NSArray *paths = NSSearchPathForDirectoriesInDomains( NSDocumentDirectory, NSUserDomainMask ,YES );
NSString *documentsDir = [paths objectAtIndex:0];
NSString *savedImagePath = [documentsDir stringByAppendingPathComponent:[NSString stringWithFormat:#"oneSlotImages%d.png", i]];
ALAssetRepresentation *rep = [[info objectAtIndex: i] defaultRepresentation];
UIImage *image = [UIImage imageWithCGImage:[rep fullResolutionImage]];
//----resize the images
image = [self imageByScalingAndCroppingForSize:image toSize:CGSizeMake(256,256*image.size.height/image.size.width)];
NSData *imageData = UIImagePNGRepresentation(image);
[imageData writeToFile:savedImagePath atomically:YES];
Thanks for the help. Much Appreciated.
You could always keep a list of used names and do something like this
int i = 1;
while([listOfUsedNames containsObject:nextAvailableTile]) {
nextAvailableTitle = [kDefaultImageName stringByAppendingFormat:#" %d", i];
i++;
}
// found an unused name
The URL for each image is unique right? So we can make use of this. Convert the URL into MD5 string (which form a unique identifier for each image). And save with that name (like "MD5string.png").
Why can't we use this?
Hope this helps you.
For converting to MD5, please create a file named NSString+MD5.h and put the code
#import <Foundation/Foundation.h>
#import <CommonCrypto/CommonDigest.h>
#interface NSString(MD5)
- (NSString *)MD5;
#end
in it.
Then in the NSString+MD5.m,
#import "NSString+MD5.h"
#implementation NSString(MD5)
- (NSString*)MD5
{
const char *ptr = [self UTF8String];
unsigned char md5Buffer[CC_MD5_DIGEST_LENGTH];
CC_MD5(ptr, strlen(ptr), md5Buffer);
NSMutableString *output = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++)
[output appendFormat:#"%02x",md5Buffer[i]];
return output;
}
#end
Import the NSString+MD5.h class where ever you want to use the MD5 function with normal NSString object.
In you code if you have the UIImagePickerControllerMediaURL string, since it is unique for every file you can convert in to MD5 String like
NSString *imgURL = [NSString stringWithString: UIImagePickerControllerMediaURL];
NSString *MD5String = [imgURL MD5];
NSString *savedImagePath = [documentsDir stringByAppendingPathComponent:[NSString stringWithFormat:#"%#.png", MD5String]];
Use that path to save your image file.
On Loading,
Convert the UIImagePickerControllerMediaURL into MD5 and check in the Documents directory for the file
// In this the UIImagePickerControllerMediaURL is the URL of media file to load
NSString *imgURL = [NSString stringWithString: UIImagePickerControllerMediaURL];
NSString *MD5String = [imgURL MD5];
NSString *savedImagePath = [documentsDir stringByAppendingPathComponent:[NSString stringWithFormat:#"%#.png", MD5String]];
Then do the checking with the fileExistsAtPath method of NSFileManager and if exists then load the file from the path. Thats it.
Note: For this you want to keep the UIImagePickerControllerMediaURL of the images you saved in documents directory locally somewhere in your app (In DB or NSUserDefaults) for make use of then at the time of loading.
Try this:
NSMutableString *imageName = [[[NSMutableString alloc] initWithCapacity:0] autorelease];
CFUUIDRef theUUID = CFUUIDCreate(kCFAllocatorDefault);
if (theUUID) {
[imageName appendString:NSMakeCollectable(CFUUIDCreateString(kCFAllocatorDefault, theUUID))];
CFRelease(theUUID);
}
[imageName appendString:#".png"];
The user can choose whether he wants to use an existing image or take a new one for use as the background.
Everything works as far as the FirstViewController is concerned. Sadly the image is no longer set as the background, when the SecondViewController is displayed.
How do I enable the use of the image as background for the SecondViewController?
I used this piece of code (in the SecondViewController):
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
int bla = [prefs integerForKey:#"background_key"];
if (bla == 1) {
self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"1.mac.jpg"]];
} else if (bla == 2) {
self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"black.jpg"]];
} else if (bla == 3) {
self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"pinn.png"]];
} else if (bla == 4) {
self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"MyImage.png"]];
}
I tried to save the chosen image as "MyImage.png" but it looks as though it did not work. The background is black instead of the image selected.
I used this code (from the 1stViewController) to save the chosen picture as "MyImage.png":
- (void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)anInfo {
//UIImage *selectedImage;
NSURL *mediaUrl;
mediaUrl = (NSURL *)[anInfo valueForKey:UIImagePickerControllerMediaURL];
if (mediaUrl == nil)
{
selectedImage = (UIImage *) [anInfo valueForKey:UIImagePickerControllerEditedImage];
if (selectedImage == nil)
{
selectedImage = (UIImage *) [anInfo valueForKey:UIImagePickerControllerOriginalImage];
NSLog(#"Original image picked.");
}
else
{
NSLog(#"Edited image picked.");
}
}
[picker dismissModalViewControllerAnimated:YES];
if (selectedImage != nil)
{
self.view.backgroundColor = [UIColor colorWithPatternImage:selectedImage];
}
// Get the image from the result
UIImage* ownImage = [anInfo valueForKey:UIImagePickerControllerOriginalImage];
// Get the data for the image as a PNG
NSData* imageData = UIImagePNGRepresentation(ownImage);
// Give a name to the file
NSString* imageName = #"MyImage.png";
// Now, we have to find the documents directory so we can save it
// Note that you might want to save it elsewhere, like the cache directory,
// or something similar.
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString* documentsDirectory = [paths objectAtIndex:0];
// Now we get the full path to the file
NSString* fullPathToFile = [documentsDirectory stringByAppendingPathComponent:imageName];
// and then we write it out
[imageData writeToFile:fullPathToFile atomically:NO];
return;
}
There must be a mistake or logical mistake.
Help would be appreciated!
ImageNamed is generally used to load images that are included as part of the resources of an application.
I suspect you want:
UIImage* image = [UIImage imageWithContentsOfFile:fileNameAndPath];
Try loading the image with similar code to how you save it instead of using +imageNamed:: build the full path and load it from there.
+imageNamed: "looks for an image with the specified name in the application’s main bundle." (UIImage reference), but that's not where you are saving it to. I don't think you can write into the application's bundle, so you won't be able to use +imageNamed: here.
I'm saving some data using a series of NSDictionaries, stored in an NSMutableArray and archived using NSKeyedArchiver.
I'm basically trying to save the states of several instances the class 'Brick', so I've implemented a getBlueprint method like this (slimmed down version)
-(id)getBlueprint
{
// NOTE: brickColor is a string
NSDictionary *blueprint = [NSDictionary dictionaryWithObjectsAndKeys:
brickColor, #"color",
[NSNumber numberWithInt:rotation], #"rotation",
nil];
return blueprint;
}
And so I have another method that creates a new Brick instance when provided with a blueprint.
-(id)initWithBlueprint:(NSDictionary *)blueprint spriteSheet:(NSString *)ssheet
{
if((self == [super init])){
brickColor = [blueprint objectForKey:#"color"];
[self setColorOffset:brickColor];
while(rotation != [[blueprint objectForKey:#"rotation"] intValue]){
[self setRotation:90];
}
}
return self;
}
Which works when I pass it a 'fresh' blueprint, but not when I read a blueprint from a saved file... sort of. For example, the rotation will work, but changing the color wont. So while I can read the value of brickColor using
NSLog(#"brick color %#", [blueprint objectForKey:#"color"]);
if I try something like
if(brickColor == #"purple"){
colorOffset = CGPointMake(72,36);
NSLog(#"Changed offset for -- %# -- to %#", color, NSStringFromCGPoint(colorOffset));
}
And I know that color is purple, the condition doesn't return true. I thought it might be that somehow NSKeyedUnarchiver changed a string into something else, but the following test returns true.
if([color isKindOfClass:[NSString class]]){
NSLog(#"%# IS A STRING", color);
}else{
NSLog(#"!!!!! COLOR IS A NOT STRING !!!!!");
}
As I said, this isn't a problem if I try to use a freshly created NSDictionary as a blueprint, only when a blueprint is archived and then read back in.
So, as usual, I'm wondering if anyone has any ideas why this might be happening.
incase it's relevant, here's how the data is being stored and recieved.
// Saving
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
-(void)buildLevelData{
levelData = [[NSMutableArray alloc] initWithCapacity:100];
for(brickSprite *brick in spriteHolder.children){
[levelData addObject:[brick getBlueprint]];
}
}
-(void)saveLevel
{
[self buildLevelData];
NSData *rawDat = [NSKeyedArchiver archivedDataWithRootObject:levelData];
if([self writeApplicationData:rawDat toFile:saveFileName]){
NSLog(#"Data Saved");
}else{
NSLog(#"ERROR SAVING LEVEL DATA!");
}
[[Director sharedDirector] replaceScene:[MainMenu scene]];
}
- (BOOL)writeApplicationData:(NSData *)data toFile:(NSString *)fileName {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
if (!documentsDirectory) {
NSLog(#"Documents directory not found!");
return NO;
}
NSString *appFile = [saveDir stringByAppendingPathComponent:fileName];
return ([data writeToFile:appFile atomically:YES]);
}
// Loading
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
- (void) loadRandomMapFrom:(NSString *)dir
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsDir = [paths objectAtIndex:0];
if(!docsDir){
NSLog(#"Cound Not Find Documents Directory When trying To Load Random Map");
return;
}
dir = [docsDir stringByAppendingPathComponent:[NSString stringWithFormat:#"/%#", dir]];
// we'll also set the file name here.
NSArray *existingFiles = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:dir error:nil];
// get last file for this test
NSString *filePath = [dir stringByAppendingPathComponent:[existingFiles objectAtIndex:([existingFiles count] - 1)]];
NSMutableArray *levelData = [NSKeyedUnarchiver unarchiveObjectWithFile:filePath];
[self buildMapWithData:levelData];
}
-(void)buildMapWithData:(NSMutableArray *)lData
{
for(NSDictionary *blueprint in lData){
brickSprite *brick = [[brickSprite alloc] initWithBlueprint:blueprint spriteSheet:#"blocks.png"];
[spriteHolder addChild:brick];
}
}
Sorry about the mess of a question. There's a lot going on that I'm struggling to fully understand myself so it's hard to break it down to the bare minimum.
You should always compare strings with [firstString isEqualToString:secondString], because firstString == secondString only checks for pointer equality, e.g. if both strings are stored at the same location (which they'll never be when comparing dynamically created objects and string constants).