问计算器的方案是什么？

EN

- (IBAction)btnColetorClick:(id)sender
{
    NSString *customURL = @"calculator://";

    if ([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:customURL]])
    {
        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:customURL]];
    }
    else
    {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"URL error"
                                                        message:[NSString stringWithFormat:@"No custom URL defined for %@", customURL]
                                                       delegate:self
                                              cancelButtonTitle:@"Ok"
                                              otherButtonTitles:nil];
        [alert show];
    }
}