quicklook not showing image but has right data

Question

i'm using quicklook to preview an image saved locally. when i run the app, quicklook read the right file and has the right image memory but doesn't preview it. it shows me something like this.

in my code i'm passing an NSURL to this delegate method

(id)previewController:(QLPreviewController *)previewController previewItemAtIndex:(NSInteger)idx so i guess everything is in place. but what could i missing?

EDIT: to creath the path i do it by the following:

filePath = [NSString stringWithFormat:@"%@/LeBaccPictureDownloadedTemperoraly", [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]];

and in the delegate method i mentioned i return the url by this:

[NSURL fileURLWithPath:filePath];

Answer 1

does filePath = [@"~/Documents/LeBaccPictureDownloadedTemperoraly" stringByExpandingTildeInPath]; change anything? Does the file have an extension? Try to show the file in an UIImageView to make sure the file is not broken. Whatch the file format xD

Like this?