Copy file to documents directory (sandbox) from main bundle

I need to copy some png to documents folder from the main bundle at the first run of my app. I need it because I have to save the file path of these images in a core data entity.

I tried in that way, but it don't works, anybody knows why?

// to copy image from main bundle to documents folder

NSString* mainBundleFilePath = [[NSBundle mainBundle] pathForResource:@"SbriciolataDiRicotta" ofType:@"png"];

NSArray *destPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [destPath objectAtIndex:0];

 NSData *mainBundleFile = [NSData dataWithContentsOfFile:mainBundleFilePath];
[[NSFileManager defaultManager] createFileAtPath:documentsDirectory
                                        contents:mainBundleFile
                                      attributes:nil];

// to save the file path

NSString*nomeImmagine = [[NSString alloc] initWithFormat:@"SbriciolataDiRicotta"];
NSString *pngFilePath = [NSString stringWithFormat:@"%@/%@.png",documentsDirectory, nomeImmagine];

Thanks

createFileAtPath expects as argument the path of file to be created, not the path of the enclosing directory.

Remarks:

• You can also use copyItemAtPath:toPath:error: to copy the file without loading the entire contents into memory.
• The usage of initWithFormat to assign a constant string is unnecessary.
• stringByAppendingPathComponent: is the correct method to append a path component.