I'm trying to display a BLOB image (get from web server using Json) in my iOS app, but when I run my application I get an empty UIimageView, here is my code :
NSData *dataURL = [NSData dataWithContentsOfURL:[NSURL URLWithString:encodedUrl]];
NSData *profileImage1 = [[NSData alloc] initWithBytes:[dataURL bytes] length:[dataURL length]];
UIImage *profileImage2 = [UIImage imageWithData:profileImage1];
[profilImage setImage:profileImage2];
How can I fix this problem?
[UIImage imageWithData:data] only parses known image file formats like JPEG, PNG, etc. (Full info in the decomentation). Passing blobs isn't supported by UIImage. You need to do some decoding to be able to use the data for the UIImage. You can use GMTBase.64 for encoding and decoding of data. Read the docs and other posts and you'll find out how to change your code.
Hope this helps.
Related
http://hauwengweb.azurewebsites.net/api/AccomodationImages/images/1
I'm trying to download image on imageView. If you will paste this url on browser it will show, but on imageView it's not showing. If you will try any other image, then the same code will work, but when I used this url, the image does not show.
The image in question seems to be a WebP image (served with the wrong MIME type of image/png), which is not a format natively supported by UIImage. However, you can use iOS-WebP to decode the image:
Add the framework, header and implementation to your project, then use:
#import "UIImage+WebP.h"
NSURL *url = [NSURL URLWithString:#"http://hauwengweb.azurewebsites.net/api/AccomodationImages/images/1"];
NSData *data = [NSData dataWithContentsOfURL:url];
imageView.image = [UIImage imageWithWebPData:data];
And please remember to do the download and decoding steps asynchronously so as not to block the main UI.
Try this?
NSURL *url = [NSURL URLWithString:#"http://hauwengweb.azurewebsites.net/api/AccomodationImages/images/1"];
NSData *data = [NSData dataWithContentsOfURL:url];
self.img.image = [UIImage imageWithData:data];
Edit
The URL you provided is not an absolute path hence the data being fetched cannot be converted into an UIImage. There is something wrong with the URL or the formatting of it.
I am attempting to load image files as an NSString, but all of them come up nil using this code:
NSString *path = [[NSBundle mainBundle] pathForResource:[NSString stringWithUTF8String:name.data()] ofType:nil];
NSString *da = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
I am able to load many files, but all JPEG and PNG files fail for some reason. I thought it might have something to do with encoding so I switched it to usedEncoding, but it still didn't work.
What am I missing?
EDIT:
I have been making an iOS/Android cross platform OpenGL graphics library in C++. Everything works except texture loading. Any file loading from disk goes through one function that is abstracted between systems. I need the image file in an STL string, so that I can pass it to an image parsing library to get the raw pixel data.
I just think that it's reduculous that the function I have can open any file except images.
If you run your code, passing an NSError instance instead of nil,
NSError *error = nil;
NSString *string = [NSString stringWithContentsOfFile:filePath
encoding:NSUTF8StringEncoding
error:&error];
you will see that stringWithContentsOfFile cannot open the image file, returning nil and the error given is:
Error Domain=NSCocoaErrorDomain Code=261 "The operation couldn’t be completed. (Cocoa error 261.)"...
Cocoa error 261 is NSFileReadInapplicableStringEncodingError which means the encoding of the file is different from the one you are passing (NSUTF8StringEncoding). But I have tried with the other encodings, and none works for PNG files.
You can still achieve what you want by loading the file as a UIImage and then converting the UIImage into a Base64 string.
Since iOS 7, this is easier because you can use the built in method base64EncodedStringWithOptions:
// Load the image and convert it to NSData
UIImage *image = [UIImage imageNamed:#"yourImageName"];
NSData *imageData = UIImagePNGRepresentation(image);
// You can use the equivalent UIImageJPEGRepresentation() for JPEG images
// Convert NSData to a Base64 NSString
NSString *base64ImageString = [imageData base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
Previous to iOS 7, you can do the exact same thing but you will have to implement your own Base64 encoding method (Or import any of the many already available, eg. nicklockwood/Base64).
In my project i need to show the different sizes of images in zig-zag fashion. so, i converted the uiimages(url) which are coming from service to NSData and then i get the uiimage. my code is
NSURL *url = [NSURL URLWithString:[[_result objectAtIndex:i ] valueForKey:#"PImage"]];
NSData *data = [NSData dataWithContentsOfURL:url];
UIImage *image = [UIImage imageWithData:data];
so i can get the image size(width and height), But my problem is according to the image size, i need to create UIView, this code is works fine for me, but it is taking too much of time(almost 25 sec) to load 8 images. i figured converting UIImage to NSData is taking time. Is there any way to get the image size(width and height) without converting it into NSData
Thanks for spending time for me.
You can get image properties without actually loading whole image data from disk using ImageIO framework:
#import ImageIO;
...
NSURL *imageURL = … // Init URL somehow
CGImageSourceRef imgSource = CGImageSourceCreateWithURL((__bridge CFURLRef)url, NULL);
NSDictionary* imageProps = (__bridge_transfer NSDictionary*) CGImageSourceCopyPropertiesAtIndex(imgSource, 0, NULL);
NSLog(#"%#", imageProps);
CFRelease(imgSource);
Image width and height will be stored in dictionary under PixelHeight and PixelWidth keys (tested with png image, may be other image formats will use different keys)
Instead of converting url to data and to UIImage, Use EGOImageView OR AsyncImageView. You can simply pass the URL to them. Again setFrame based on size of the image.
Im trying to attach a Google Maps image to an email generated in my app, however Google Maps does not return a specific image from its url. If I search a url with .png etc at the end of it, I can get the image fine, but how can I get the image from a site that doesn't have that,
ie:
http://maps.googleapis.com/maps/api/staticmap?size=200x200&maptype=roadmap\\&markers=size:mid%%7Ccolor:red%%7CNew+York&sensor=false
Im using NSData dataWithContentsOfURL: which then attaches to my email.
I have also tried to open the url in an iframe within the email with the same result, works with a .png url, not maps.
Any help would be greatly appreciated, thanks.
Try this,
NSString *urlString = #"http://maps.googleapis.com/maps/api/staticmap?size=200x200&maptype=roadmap\\&markers=size:mid%%7Ccolor:red%%7CNew+York&sensor=false";
NSString *encodedString=[urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *webURL = [NSURL URLWithString:encodedString];
NSData *myData = [NSData dataWithContentsOfURL:webURL];
UIImage *image = [[UIImage alloc] initWithData:myData];
self.imageView.image = image;
http://maps.googleapis.com/maps/api/staticmap?size=200x200&maptype=roadmap%%5C&markers=size:mid%%257Ccolor:red%%7CNew+York&sensor=false
Just needed to edit some of the % \ etc to incorporate the UTF8 encoding, however if you use the encoding method karthika suggested, it breaks the search. All I did was hard code the string and removed the added encoding before the address and its working perfectly.
I am caching an NSData object containing image data retrieved from the web. The image displays correctly before caching. When I retrieve the data object from the cache, the data can no longer be used to create a UIImage, even though the data objects are identical.
Please see the relevant snippets of my code below
NSData *webData= [NSData dataWithContentsOfURL:webPath]; //retrieve from web
UIImage *webImage = [UIImage imageWithData:webData]; //works fine
[webData writeToURL:filePath atomically:YES]; //cache
NSData *cacheData = [NSData dataWithContentsOfURL:filePath]; //get from cache
if ([cacheData isEqualToData:webData]) NSLog(#"Equal"); //Data objects are equal
UIImage *cacheImage = [UIImage imageWithData:cacheData]; //cacheImage is nil
I can fix the problem by changing the way I store my data to the cache
NSData *temp = UIImageJPEGRepresentation(webImage, 1.0):
[temp writeToURL:filePath atomically:YES];
Now the webData and cacheData are no longer equal, but cacheImage is not nil and displays properly.
EDIT - After a bit more testing, I realized I get the same problem using UIImageJPEGRepresentation as well.
Anyone know why this would be?
Thanks.
Figure out the problem was that I was trying to do all this before my view controller was fully loaded.