将NSMutableDictonary添加到NSMutableArray但是要替换的对象

Question

为什么每当我向NSMutableArray添加一个新对象NSMutableDictionay时它会替换我之前的对象？

例如：

[appDelegate.tracksDict setObject:currentTrackTitle forKey:@"track_title"];
[appDelegate.tracksDict setObject:currentTrackTopic forKey:@"topic"];
[appDelegate.tracksArray addObject:[appDelegate.tracksDict copy]];

它的印刷......

2010-10-01 14:03:35.021 XML[48889:207]Tracks Array: {
    topic = "Cold Calling";
    "track_title" = "Sleeping and selling";
}
2010-10-01 14:03:35.021 XML[48889:207]Tracks Array: {
    topic = "Gate Keeper";
    "track_title" = "Selling like a chicken";
}
2010-10-01 14:03:35.021 XML[48889:207]Tracks Array: {
    topic = "Gate Keeper";
    "track_title" = "Don't you try to sell";
}

而不是...... ...

2010-10-01 14:03:35.021 XML[48889:207]Tracks Array: {
    topic = "Cold Calling";
    track_title = "Sleeping and selling";

    topic = "Gate Keeper";
    track_title = "Selling like a chicken";

    topic = "Gate Keeper";
    track_title = "Selling like a chicken";
}

我确信这是愚蠢的，因为我不太熟悉这种语言。

Answer 1

根据您发布的“打印”，您的问题难以理解，但听起来您需要NSArray的NSDictionary对象。 NSDictionary只能为给定的密钥保存单个对象，但可以拥有（几乎）无限密钥。看起来你需要的是构建一个字典数组，每个轨道一个。