NSInteger _downloads;

-(IBAction)refresh:(id)sender{
    if (_downloads == 0) {
    [self refreshAction];
    }
}

- (void)downloadStarted {
    _downloads++;
}

- (void)downloadFinished {
    _downloads--;
    if (_downloads == 0 && self.refreshControl.refreshing) {
        [self refreshAction];
    }
}