UIImagePickerController's object in NSMutableArray

I need to add objects selected by UIImagePicker开发者_如何转开发Controller into an NSMutabeArray, the code goes as:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {

    [picker dismissModalViewControllerAnimated:YES];

    if(![imagesArray containsObject:[info objectForKey:@"UIImagePickerControllerOriginalImage"]])
        {
        [imagesArray addObject:[info objectForKey:@"UIImagePickerControllerOriginalImage"]];

        } 
    else {
           //some procedures
            }
}

The problem is that it always fells into the if block and never executes the else block when picking same images repeatedly. Any clue over this would be appreciated.

I think your problem is that two instances of UIImage can't be compared using isEqual:, which containsObject: is using, even if they point to the same image file. I don't know how to compare two UIImage but you can perhaps look at Generate hash from UIImage or search for "comparing UIImage".

Check by casting. Add it in this way:

UIImage *img =[info objectForKey:@"UIImagePickerControllerOriginalImage"];
if(![imagesArray containsObject:img])
 [imagesArray addObject:img];