I m pretty new to iPhone development. I'm trying to implement scroll view with loading images dynamically from web. I m trying to use the following code.
for (counter = 0; counter < 2; counter++) {
RSSEntry *entry = [_allEntries objectAtIndex:counter];
NSData * imageData = [[NSData alloc] initWithContentsOfURL: [NSURL URLWithString: entry.articleUrl]];
UIImage *img = [UIImage imageWithData: imageData];
NSLog(#"%#", entry.articleUrl);
UIImageView *imageView = [[UIImageView alloc] initWithImage:img];
[imageData release];
CGRect rect = scrollViewController.frame;
imageView.frame = rect;
imageView.tag = (counter + 1); // tag our images for later use when we place them in serial fashion
[scrollViewController addSubview:imageView];
[imageView release];
}
These are two images that I load up on viewDidLoad. I want to load the next image when the user scroll onto the second image and if the user scroll next want to show that the image is loading. Any suggestion?
You muse use NSURLConnection and download the images asynchronously. You can use TCImageView
https://github.com/totocaster/TCImageView
It downloads the images in an async way.
I would also recommend Three20's TTImageView.
Related
I have an app which loads an image from the local disk and then displays it on a UIImageView. I want to set the image to aspect scale to fit.
The problem I'm having is that the imageOrientation is coming back as UIImageOrientationRight even though it's a portrait image and that's messing with how the aspect calculations are done.
I've tried a few methods of changing the meta data but both rotate the image when it gets displayed.
UIImageView *iv = [[UIImageView alloc] initWithFrame:self.frame.frame];
NSMutableString *path =[[NSMutableString alloc] initWithString: [[NSBundle mainBundle] resourcePath]];
[path appendString:#"/pic2.jpg"];
NSData *data = [NSData dataWithContentsOfFile:path];
UIImage *img = [UIImage imageWithData:data];
UIImage *fixed1 = [UIImage imageWithCGImage:[img CGImage]
scale:1.0
orientation: UIImageOrientationUp];
UIImage *sourceImage = img;
UIImage *fixed2 = [UIImage
imageWithCGImage:[img imageRotatedByDegrees:90].CGImage
scale:sourceImage.scale
orientation:UIImageOrientationUp];
iv.image = fixed1; // fixed2;
[iv setContentMode:UIViewContentModeScaleAspectFill];
[self.view addSubview:iv];
In the end I took a different approach and made the UIImageView 360 wide and placed it in the centre and this achieved the desired effect.
could you please provide me by sample code for creation a UIImage object with specific width and height programmatically in the code then load an Image in it which supposed to fetch from json (it has to be an image URL).
If I use synchronous network request for loading the picture does it block my UI till loading be completed or not? if so what's the solution?
Thanks in Advance
Pull out the image URL from your json data, download the image, and then use the image as needed.
NSString *imageURL = url from your json string;
NSURL *url = [NSURL URLWithString:imageURL];
UIImageView *imageView = [UIImageView alloc] initWithFrame:CGRectMake(0,0,50,75)];
[yourParentView addSubview: imageView];
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, ^{
UIImage *image = [UIImage imageWithData: [NSData dataWithContentsOfURL:url]];
dispatch_sync(dispatch_get_main_queue(), ^{
imageView.image = image;
CGRect frame = CGRectMake(imageView.origin.x, imageView.origin.y, image.size.width, image.size.height);
imageView.frame = frame;
});
});
i create an nsmutableArray and i add for it an images. also i create an imageView that i want to show the images from the array, i tried to use animationImages but i nothing is happened, how can i fix it?
here is my code:
//Numbers images
UIImage *numberZero = [UIImage imageNamed:#"numberZero.png"];
UIImage *numberOne = [UIImage imageNamed:#"numberOne.png"];
UIImage *numberTwo = [UIImage imageNamed:#"numberTwo.png"];
UIImage *numberThree = [UIImage imageNamed:#"numberThree.png"];
UIImage *numberFour = [UIImage imageNamed:#"numberFour.png"];
UIImage *numberFive = [UIImage imageNamed:#"numberFive.png"];
UIImage *numberSix = [UIImage imageNamed:#"numberSix.png"];
UIImage *numberSeven = [UIImage imageNamed:#"numberSeven.png"];
UIImage *numberEight = [UIImage imageNamed:#"numberEight.png"];
UIImage *numberNine = [UIImage imageNamed:#"numberNine.png"];
//add numbers uiimage to numbersArray
numbersArray = [NSMutableArray arrayWithObjects:numberZero, numberOne, numberTwo, numberThree, numberFour, numberFive, numberSix, numberSeven, numberEight, numberNine, nil];
imgview1 = [[UIImageView alloc] init];
imgview1.animationImages = numbersArray;
imgview1.animationDuration = 2;
imgview1.animationRepeatCount=0;
[imgview1 startAnimating];
[imgview1 stopAnimating];
thanks!
You need to actually add imgview1 to something so that it displays. If imgview1 was created in Interface Builder then there is no need to assign. Also you stop your animation immediately after starting it.
//If created in IB comment out the next line
imgview1 = [[UIImageView alloc] init];
imgview1.animationImages = numbersArray;
imgview1.animationDuration = 2;
imgview1.animationRepeatCount=0;
//If not created in IB then add this to a view e.g:
[self.view addSubview:imgview1];
[imgview1 startAnimating];
//[imgview1 stopAnimating]; this is too soon to stop animating
I assume that by "nothing happened" you mean that you see the first image, but the sequence does not move beyond that.
This is probably because you stopAnimating too soon: it does not even get a chance to start!
i solve the problem, i guess the problem were because i didn't use init with frame to my imgview.
here is the final code:
UIImageView *imgview1 = [[UIImageView alloc] initWithFrame:CGRectMake(40, 90, 240, 240)];
imgview1.animationImages = numbersArray;
imgview1.animationDuration = 2;
imgview1.animationRepeatCount=1;
[imgview1 startAnimating];
[self.view addSubview:imgview1];
hope u understand...
I am beginner of iphone, I have all images in array but how to display one by one when I execute the array in a loop..
NSArray *images = [[NSArray arrayWithObjects:
[UIImage imageNamed:#"1.png"],
[UIImage imageNamed:#"2.png"],
[UIImage imageNamed:#"3.png"],
[UIImage imageNamed:#"4.png"],
nil] retain];
int i=0;
int width = 0;
int height = 0;
for ( NSString *imageName in images )
{
//NSTimer *timer=[[NSTimer alloc]init];
UIImage *image = [images objectAtIndex:i];
//UIImage *image = [UIImage imageNamed:imageName];
animalphoto = [[UIImageView alloc] initWithImage:image];
animalphoto.contentMode = UIViewContentModeScaleAspectFit;
animalphoto.clipsToBounds = YES;
animalphoto.animationDuration=5.0;
animalphoto.animationRepeatCount=0;
animalphoto.frame = CGRectMake( animalphoto.frame.size.width * i++, 0, animalphoto.frame.size.width, animalphoto.frame.size.height);
width = animalphoto.frame.size.width;
height = animalphoto.frame.size.height;
NSLog(#"print:%#",image);
[animalphoto release];
}
}
Give any suggestion and sample code which is apply in our code..
Instead of putting one image just put whole array of images to the imgview.animationImages = images without the for loop
For further reference visit this site.
you need to use UIImageView's object animationImages to set the UIImage array
set animationRepeatCount
set animationDuration
then call [imageView startAnimating]; to start the animation
i found an issue with Photo Library Images. It not displaying first time in my View,Image View is blank while loading first time.
Because i found Asset Library block working on another thread.After reloading my View ,I can see all the Images. However first time the Image Views are Blank.
can any one tell me a good way to deal with the problem
It working with Bundle Images.
also some times console shows that
app is crashing due to Program received signal: “0”. Data Formatters temporarily unavailable, will re-try after a 'continue'. (Unknown error loading shared library "/Developer/usr/lib/libXcodeDebuggerSupport.dylib")
My Code:
for (int j = 0; j<9; j++)
{
//allocating View
UIView *smallView = [[UIView alloc] initWithFrame:CGRectMake(xCordImage, yCordImage, 200, 190)];
// allocating ImageView
imageViewTopic = [[[UIImageView alloc] init] autorelease];
typedef void (^ALAssetsLibraryAssetForURLResultBlock)(ALAsset *asset);
typedef void (^ALAssetsLibraryAccessFailureBlock)(NSError *error);
ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myasset)
{
ALAssetRepresentation *rep = [myasset defaultRepresentation];
CGImageRef iref = [rep fullResolutionImage];
UIImage *images;
if (iref) {
images = [UIImage imageWithCGImage:iref];
}
else {
images = [UIImage imageNamed:#"Nofile.png"];
}
imageViewTopic .image = images ;
};
ALAssetsLibraryAccessFailureBlock failureblock = ^(NSError *myerror)
{
imageViewTopic .image = [UIImage imageNamed:#"Nofile.png"];
NSLog(#"booya, cant get image - %#",[myerror localizedDescription]);
};
NSString *string ;
MyClass *obj = [imageFileNameArray objectAtIndex:j];
**//obj.fileName contains ALAsset URL of a Image**
string = obj.fileName;
NSURL *asseturl = [NSURL URLWithString:string];
ALAssetsLibrary* assetslibrary = [[[ALAssetsLibrary alloc] init] autorelease];
[assetslibrary assetForURL:asseturl resultBlock:resultblock
failureBlock:failureblock];
imageViewTopic.userInteractionEnabled = YES;
imageViewTopic.frame = CGRectMake(0,0, 200, 150);
[currentView addSubview:scroller];
**// adding the imageView to View**
[smallView addSubview:imageViewTopic];
[myView addSubview:smallView];
[scroller addSubview:myView];
}
I am using this method to show images in scroll view with lazy loading. It works well.
First initialize the value of j1. And data is the image data coming from loop from an array.
dispatch_async(dispatch_get_global_queue(0,0), ^{
NSData * data = [[NSData alloc] initWithContentsOfURL:url];
if ( data == nil )
return;
dispatch_async(dispatch_get_main_queue(), ^{
__block int j1=_j;
// WARNING: is the cell still using the same data by this point??
// NSURL *url = [NSURL URLWithString: imageName];
UIImage *image = [UIImage imageWithData: data]; //image.size.height
image1=[[UIImageView alloc] initWithFrame:CGRectMake(j1,10,image.size.width,image.size.height)];
image1.image=image;
CALayer *layer = [image1 layer];
[layer setMasksToBounds:YES];
[layer setCornerRadius:0.0]; //note that when radius is 0, the border is a rectangle
[layer setBorderWidth:3.0];
[layer setBorderColor:[[UIColor whiteColor] CGColor]];
[portfolio_scroll addSubview:image1];
});
});
_j = _j+ 320;