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iosobjective-cuiimagensdataurl-shortener

NSData from Shorted URL not make UIImage

I am facing problem with downloading a .jpg image using a shorted URL like this one:

shorted URL:- https://db.tt/KH5NgfT1

I got successfully NSData length of 41791 bytes. But problem is when I convert this NSData to UIImage it gives NULL and when this NULL image I am posting on faceBook It successfully posted to my facebook account, for post on facebook I am using SLComposeViewController and one thing more that is this Image is also not shown in SLComposeViewController.

I am using this code for download image 

NSData *downloadedImageData=[NSData dataWithContentsOfURL:[NSURL URLWithString:shortedURL]];

Convert to UIImage

UIImage *image=[UIImage imageWithData:downloadedImageData];

returns NULL image

and My SLComposeViewController look like this

My SLComposeViewController screenshot

I want to show downloaded image in SLComposeViewController

Solution

  • NO erkanyildiz maybe your above answer is wrong because there is no difference between long and shorted URL they both redirect me to a image once look at this

    1. this shorted url not works because it's from DropBox

      NSData *imageData=[NSData dataWithContentsOfURL:[NSURL URLWithString:@"https://db.tt/KH5NgfT1"] options:NSDataReadingUncached error:&error];
UIImage *downloadedImage=[UIImage imageWithData:imageData];

    2. this shorted url works because it's NOT from DropBox

      NSData *imageData=[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://goo.gl/FTh7No"] options:NSDataReadingUncached error:&error];
UIImage *downloadedImage=[UIImage imageWithData:imageData];

    3. this long url not works because it's from DropBox

      NSData *imageData=[NSData dataWithContentsOfURL:[NSURL URLWithString:@"https://www.dropbox.com/s/5443wq99wu9a0bu/IMG_3679.PNG"] options:NSDataReadingUncached error:&error];
UIImage *downloadedImage=[UIImage imageWithData:imageData];

    4. this long url works because it's NOT from DropBox

      NSData *imageData=[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://www.wired.com/wiredenterprise/wp-content/uploads/2013/07/20130627-DROPBOX-OFFICE-147edit.jpg"] options:NSDataReadingUncached error:&error];
UIImage *downloadedImage=[UIImage imageWithData:imageData];

    So, finally I think the problem is at DropBox server may be they have some kind of web-encription so that we can't download image directly using NSData dataWithContentsOfURL: and may be because of web-encription it support to Facebook.

    solution is DropBox provides api for downloading image https://api-content.dropbox.com/1/files//

    DropBox Core API Documentation

    Thanks for Replying