c#嵌套字典，更好的替代方案?最好地组织三个类的数据

通常，您不会看到以这种方式将包含值的对象用作键。通常，您会在对象上标识一些唯一的键，并将其用作键，将对象本身用作值。例如，可以将Person对象存储在Dictionary中，其中人名是关键字，Person是值。

您应该考虑将集合添加到对象中，而不是嵌套的Dictionary。例如，您可以将List<TrendyItem>添加到Trend以维护该关系。

这里有一种你可以组织课程的替代方法。我不太确定您的每个集合的范围是什么，但这应该会给您提供另一种看待问题的方法。

public class Trend
{
    public string TrendName { get; set; }
    public string Description { get; set; }
    // This maintains the relationship between Trend and TrendyItem
    public List<TrendyItem> Items { get; set; }
}
public class Person
{
    public string PersonName { get; set; }
    public int PersonId { get; set; }
    public int aptitude { get; set; }
    // Each person will specifiy a "TrendyItem"
    public TrendyItem Choice { get; set; }
}
public class TrendyItem
{
    public string ItemName { get; set; }
    public string ItemId { get; set; }
}
public class TrendProfile
{
    // Change this to to a key value pair. The key will be how you uniquely identify (input) the Trend in
    //2) Input: Trend; Output: List of trendy items belonging to that trend.
    // For example TrendName
    public Dictionary<string, Trend> FavoriteTrendsOfYear;
    // Change this to to a key value pair. The key will be how you uniquely identify (input) the Person in
    // 1) Input: Person; Output: List of Person's choice on trendy items.
    // For example PersonName
    public Dictionary<string, Person> ActivePeopleThisYear;

    public List<TrendyItem> TrendyItemsThisYear; 
}

有了这种课堂结构，你可以很容易地回答帖子中的问题。

static void Main()
{
    TrendProfile trendProfile = new TrendProfile();
    trendProfile.FavoriteTrendsOfYear = new Dictionary<string, Trend> {        
        { "Pizza", new Trend() {
            TrendName = "Pizza",
            Description = "yum yum",
            Items = new List<TrendyItem> {
                new TrendyItem() {ItemName = "PotatoPizza1"},
                new TrendyItem() {ItemName = "PotatoPizza2"},
                new TrendyItem() {ItemName = "PotatoPizza3"}
            }
        }},
        { "Clothing", new Trend() {
            TrendName = "Clothing",
            Description = "ba yum",
            Items = new List<TrendyItem> {
                new TrendyItem() {ItemName = "PeplumSkirt1"},
                new TrendyItem() {ItemName = "PeplumSkirt2"},
                new TrendyItem() {ItemName = "PeplumSkirt3"}
            }
        }}
    };
    trendProfile.ActivePeopleThisYear = new Dictionary<string, Person> {
        { "Arnold Palmer", new Person() { PersonName = "Arnold Palmer", Choice = trendProfile.FavoriteTrendsOfYear["Pizza"].Items[1] }},
        { "Ken Hemingway", new Person() { PersonName = "Ken Hemingway", Choice = trendProfile.FavoriteTrendsOfYear["Clothing"].Items[2] }},
    };
    //1) Input: Person; Output: List of Person's choice on trendy items.
    string person = "Arnold Palmer";
    Console.WriteLine(trendProfile.ActivePeopleThisYear[person].Choice.ItemName);
    //2) Input: Trend; Output: List of trendy items belonging to that trend.
    string trend = "Clothing";
    foreach(TrendyItem item in trendProfile.FavoriteTrendsOfYear[trend].Items)
        Console.WriteLine(item.ItemName);
}

更新

要在TrendProfiles中共享趋势，您可以首先创建趋势的"主"List或Dictionary。然后，在构建每个TrendProfiles时，您可以从"大师"中挑选趋势。

// "Master" list of trends
List<Trend> trends = new List<Trend> {
    new Trend() {
        TrendName = "Pizza",
        Description = "yum yum",
        Items = new List<TrendyItem> {
            new TrendyItem() {ItemName = "PotatoPizza1"},
            new TrendyItem() {ItemName = "PotatoPizza2"},
            new TrendyItem() {ItemName = "PotatoPizza3"}
        }
    },
    new Trend() {
        TrendName = "Clothing",
        Description = "ba yum",
        Items = new List<TrendyItem> {
            new TrendyItem() {ItemName = "PeplumSkirt1"},
            new TrendyItem() {ItemName = "PeplumSkirt2"},
            new TrendyItem() {ItemName = "PeplumSkirt3"}
        }
    }
};

TrendProfile trendProfile1 = new TrendProfile();
trendProfile1.FavoriteTrendsOfYear = new Dictionary<string, Trend> {        
    { trends[0].TrendName, trends[0] },
    { trends[1].TrendName, trends[1] }
};
TrendProfile trendProfile2 = new TrendProfile();
trendProfile2.FavoriteTrendsOfYear = new Dictionary<string, Trend> {
    { trends[1].TrendName, trends[1] }
};