What is a fast way to load 10-20 fullscreen images from a camera roll, saved photos?
I'm using this code, but to load 10 photos I need to wait about 5-10 seconds. I'm using iPhone 4S.
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
if(_savedPhotos.count>=11) *stop = YES;
[group enumerateAssetsWithOptions:NSEnumerationReverse usingBlock:^(ALAsset *result, NSUInteger index, BOOL *needToStop) {
NSLog(#"%d",index);
if(_savedPhotos.count<11)
{
UIImage *image = [UIImage imageWithCGImage:result.defaultRepresentation.fullScreenImage];
[_savedPhotos addObject:image];
}
else
{
*needToStop = YES;
}
}];
} failureBlock:^(NSError *error) {
NSLog(#"%#",error.description);
}];
The ALAssetsLibrary library will run on a separate thread. So it may take time to communicate with the UI related and other stuff.
So use -performSelectorOnMainThread:withObject:waitUntilDone: inside the ALAssetsLibrary block.
Change your code as below
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
[group enumerateAssetsWithOptions:NSEnumerationReverse usingBlock:^(ALAsset *result, NSUInteger index, BOOL *needToStop) {
NSLog(#"%d",index);
UIImage *image = [UIImage imageWithCGImage:result.defaultRepresentation.fullScreenImage];
[self performSelectorOnMainThread:#selector(usePhotolibraryimage:) withObject:image waitUntilDone:NO];
}];
}
failureBlock:^(NSError *error) {
NSLog(#"%#",error.description);
}];
- (void)usePhotolibraryimage:(UiImage *)myImage{
//Do your all UI related and all stuff here
}
Note:Look on this issue too.
Related
I am working on an iPhone application. I have an option to select existing photos from Album. There should be an option for quick access for some images as it is in iMessage. Please check the attached screenshot for more information.
Any idea ?
I found the solution for my question:
First I am reading maximum 20 recent images from Photo Album using below code. Then I am adding all the images into UIScrollView. The last one is More. If user click on it, it will show iPhone default "UIImagePickerController" to choose other images.
If anybody found a better solution, please post it.
Code
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
[group setAssetsFilter:[ALAssetsFilter allPhotos]];
[group enumerateAssetsWithOptions:NSEnumerationReverse usingBlock:^(ALAsset *asset, NSUInteger index, BOOL *innerStop) {
if (asset) {
if ([self.stackForImages count] >= 20) {
// Stop the enumerations
*stop = YES;
*innerStop = YES;
[self initializeMedia];
} else {
ALAssetRepresentation *representation = [asset defaultRepresentation];
NSMutableDictionary *workingDictionary = [[NSMutableDictionary alloc] init];
[workingDictionary setObject:[asset valueForProperty:ALAssetPropertyType] forKey:UIImagePickerControllerMediaType];
[workingDictionary setObject:[UIImage imageWithCGImage:[asset thumbnail]] forKey:UIImagePickerControllerEditedImage];
[workingDictionary setObject:[UIImage imageWithCGImage:[representation fullScreenImage]] forKey:UIImagePickerControllerOriginalImage];
[workingDictionary setObject:[[asset valueForProperty:ALAssetPropertyURLs] valueForKey:[[[asset valueForProperty:ALAssetPropertyURLs] allKeys] objectAtIndex:0]] forKey:UIImagePickerControllerReferenceURL];
[self.stackForImages addObject:workingDictionary];
}
}
}];
if ([self.stackForImages count] > 0) {
[self initializeMedia];
}
} failureBlock: ^(NSError *error) {
}];
I have used demo example of avcapture ,i wanna display image in imagview in viewcontroller after take photo i have use code
{
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
NSInteger numberOfAssets = [group numberOfAssets];
if (numberOfAssets > 0) {
NSInteger lastIndex = numberOfAssets-1;
[group enumerateAssetsAtIndexes:[NSIndexSet indexSetWithIndex:lastIndex] options:0 usingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {
UIImage *thumbnail = [UIImage imageWithCGImage:[result thumbnail]];
if (thumbnail && thumbnail.size.width > 0) {
imagviewlastimage.image = thumbnail;
*stop = YES;
}
}];
}
} failureBlock:^(NSError *error) {
NSLog(#"error: %#", error);
}];
to get last image from photo library but i am gatting second last image
and to redirect viewController after pick image i have wrote in
captureManagerStillImageCaptured:(AVCamCaptureManager *)captureManager delegate
ViewController *temp=[[ViewController alloc]init];
temp.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[self presentModalViewController:temp animated:YES];
use as this , how to resolve this ? ya pause screen after take photo
i want to get the count of photos in photoLibrary. Currently, i'am able to get the photoes from photoLibrary and add to myApp's Document directry ONE BY ONE. But what i want is, save all the photos from photoLibrary to Document directry of myApp ALL AT ONCE. Thats why i need the count of photoes in photoLibrary. I've used UIImagePickerControllerSourceTypePhotoLibrary to retrieve the photoes from iPhone photoLibrary.
Any help would be appreaciated..
thanks in advance....
Use ALAssetsLibrary for this:
int imgCount = 0;
self.assetsLibrary = [[ALAssetsLibrary alloc] init];
dispatch_queue_t dispatchQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(dispatchQueue, ^(void) {
[self.assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
[group enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index,
__block BOOL foundThePhoto = NO;
if (foundThePhoto){ *stop = YES;
}
BOOL *stop) {
/* Get the asset type */
NSString *assetType = [result valueForProperty:ALAssetPropertyType];
if ([assetType isEqualToString:ALAssetTypePhoto]){ NSLog(#"This is a photo asset");
foundThePhoto = YES; *stop = YES;
/* Get the asset's representation object */
ALAssetRepresentation *assetRepresentation = [result defaultRepresentation];
/* We need the scale and orientation to be able to construct a properly oriented and scaled UIImage out of the representation object */
CGFloat imageScale = [assetRepresentation scale];
UIImageOrientation imageOrientation = (UIImageOrientation)[assetRepresentation orientation];
dispatch_async(dispatch_get_main_queue(), ^(void) {
CGImageRef imageReference = [assetRepresentation fullResolutionImage];
/* Construct the image now */
UIImage *image = [[UIImage alloc] initWithCGImage:imageReference
scale:imageScale orientation:imageOrientation];
//Write image to doument directory
imgCount ++;
}
});
} failureBlock:^(NSError *error) {
} }];
NSLog(#"Failed to enumerate the asset groups."); }];
})
NSLog(#"Total Image Count %d",imgCount);
The code block below counts all videos and photos:
__block int videoCount = 0;
__block int photoCount = 0;
ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc]init];
[assetLibrary
enumerateGroupsWithTypes:ALAssetsGroupAll
usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
if (group == nil) {
// enumeration complete
return;
}
int total = group.numberOfAssets;
[group setAssetsFilter:[ALAssetsFilter allVideos]];
int groupVideoCount = group.numberOfAssets;
videoCount += groupVideoCount;
photoCount += total - groupVideoCount;
}
failureBlock:^(NSError *error) {
// Handle error
}];
I am trying to access iPhone's photo album photo images through ALAssetsLibrary. I could access all the photo albums and get the asset URL of each images on Simulator, via the following code:
- (void)viewDidLoad
{
[super viewDidLoad];
void (^assetEnumerator)(struct ALAsset *, NSUInteger, BOOL *) = ^(ALAsset *result, NSUInteger index, BOOL *stop) {
if(result != NULL) {
NSLog(#"See Asset: %#", result);
// assets is a NSMutableArray..
[assets addObject:result];
// Here storing the asset's image URL's in NSMutablearray urlStoreArr
NSURL *url = [[result defaultRepresentation] url];
[urlStoreArr addObject:url];
}
};
void (^assetGroupEnumerator)(struct ALAssetsGroup *, BOOL *) = ^(ALAssetsGroup *group, BOOL *stop)
{
if(group != nil) {
[group enumerateAssetsUsingBlock:assetEnumerator];
}
[self.activity stopAnimating];
[self.activity setHidden:YES];
};
assets = [[NSMutableArray alloc] init];
library = [[ALAssetsLibrary alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupAlbum usingBlock:assetGroupEnumerator failureBlock: ^(NSError *error) {
NSLog(#"Failure");
}];
urlStoreArr = [[NSMutableArray alloc] init];
}
-(void) GetURLImages
{
for (int i=0; i<[urlStoreArr count]; i++)
{
// To get the each image URL here...
NSString *str = [urlStoreArr objectAtIndex:i];
NSLog(#"str: %#",str);
}
}
It works as expected on iOS 4.0 Simulator, i.e, getting all the images URL's (ex: assets-library://asset/asset.JPG?id=1000000002&ext=JPG). But it doesn't retrieve image URL's on iPod 4.1 device. What could be the problem here? Can someone please help me fix so the code could also work on iPod? I'm totally confused.
Thank you!
Try what I mentioned in my comment or the following
library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos
It also depends what photos you want.
void (^assetGroupEnumerator)(struct ALAssetsGroup *, BOOL *) = ^(ALAssetsGroup *group, BOOL *stop)
{
if(group != nil) {
[group enumerateAssetsUsingBlock:assetEnumerator];
}
[self.activity stopAnimating];
[self.activity setHidden:YES];
/* make */ group=nil;//otherwise it is enumerated thrice.
};
I would like to know how to retrieve video format using AssetLibrary and display on uilabel? i read on forum to use ALAssetPropertyRepresentations but im just lost. some help please?
I'm not sure what you mean by "format", but this code will display the video's UTI (basically, file type) and any metadata.
ALAssetsGroupEnumerationResultsBlock assetEnumerator = ^(ALAsset *asset, NSUInteger index, BOOL *stop) {
if(asset != nil) {
ALAssetRepresentation* representation = [asset defaultRepresentation];
NSLog(#"UTI = %#", [representation UTI]);
NSLog(#"Metadata = %#", [representation metadata]);
}
};
ALAssetsLibraryGroupsEnumerationResultsBlock assetGroupEnumerator = ^(ALAssetsGroup *group, BOOL *stop) {
if(group != nil) {
[group setAssetsFilter:[ALAssetsFilter allVideos]];
[group enumerateAssetsUsingBlock:assetEnumerator];
}
};
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupAll
usingBlock:assetGroupEnumerator
failureBlock:^(NSError *error) {
NSLog(#"A problem occured. %#", error);
}];
[library release];
(Code modified from here.)
If you already have your asset, the code to update the label looks like this:
myLabel.text = [[myAsset defaultRepresentation] UTI];