按下UIAlert时在TweetSheet中添加文本

有人能告诉我当按下UIAlert标题按钮时如何在TweetSheet中添加文本吗?

目前我正在使用这个代码来实现它,但到目前为止失败了。

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
    NSString *title = [alertView buttonTitleAtIndex:buttonIndex];

    TWTweetComposeViewController *tweetSheet = [[TWTweetComposeViewController alloc] init];

    if ([title isEqualToString:@"Add custom text"]) {
        UIAlertView *alert= [[UIAlertView alloc] initWithTitle:@"Add a template" message:nil delegate:self cancelButtonTitle:@"Hi it was nice meeting you" otherButtonTitles:nil, nil];
        [alert show];
        [alert release];
    }

    if ([title isEqualToString:@"Hi it was nice meeting you"]) {
        [tweetSheet setInitialText:@"hey it was nice meeting you"];
    }

}

有人能告诉我这里出了什么问题吗?