UIAlertView *alert;        alert = [[UIAlertView alloc] initWithTitle:@"提示" message:@"题库有更新，需要更新吗？" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:@"取消", nil];        [alert setTag:1];        [alert show];

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {       if ([alertView tag] == 1) {        if (buttonIndex == 0) {     // and they clicked OK.           //更新题库        }    }    }