从一个ViewController中取一个随机数并在第二个ViewController中使用它 - Update

Question

我有两个ViewController：RedButtonViewController和TweetViewController。 RedButtonViewController在文本标签中生成随机数字，我想用TweetViewController来使用数字或标签。我怎样才能做到这一点？

感谢您的帮助！

我TweetViewController将与此代码在RedButtonViewController打开：

- (IBAction)TweetViewController:(id)sender { 
    TweetViewController *Tweet = [[TweetViewController alloc] initWithNibName:nil bundle:nil]; 
    [self presentModalViewController:Tweet animated:YES]; 
} 

下面是我如何生成随机数的为例：

- (IBAction)pushRedButton:(UIButton *)sender { 

    int ZahlDerToten; 
    ZahlDerToten = arc4random() % 1000000; 

    outputLabel.text = [NSString stringWithFormat:@"You killed %d people.", ZahlDerToten]; 

Answer 1

在TweetViewController并设置创建一个属性它提出之前：

- (IBAction)TweetViewController:(id)sender { 
    // Note: don't put leading capitals on a local variable 
    TweetViewController *tweet = [[TweetViewController alloc] initWithNibName:nil bundle:nil]; 
    tweet.randomNumber = [self generateRandomNumber]; 
    [self presentModalViewController:tweet animated:YES]; 
    // Note: You were leaking the view controller 
    [tweet release]; 
} 

另一种解决方案（和怎么我通常做这种事情）是创建一个名为-initWithNumber:（可能的东西有点不是“数字”更具描述性的新的初始化），并调用它像这样：

- (IBAction)TweetViewController:(id)sender { 
    TweetViewController *tweet = [[TweetViewController alloc] initWithNumber:[self generateRandomNumber]]; 
    [self presentModalViewController:tweet animated:YES]; 
    [tweet release]; 
} 

-initWithNumber然后会看起来像：

- (TweetViewController *)initWithNumber:(NSInteger)number { 
    self = [super initWithNibName:nil bundle:nil]; 
    if (self != nil) { 
     self.number = number; 
    } 
    return self; 
}