Detect backspace in UITextField

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    if (range.length > 0 && [text isEqualToString:@""]) {
        NSLog(@"press Backspace.");
    }
    return YES;
}

(OR)

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{

if ([string isEqualToString:@""]) {

        return YES;

    }
}