将元组项填充为字典中的列表

Question

我的代码中有一个Dictionary，在一个方法中定义为：

public Dictionary<int, Tuple<List<int>, int, int, int>> GetAuthorData(int startYear, int endYear)  
{  
   Dictionary<int, Tuple<List<int>>, int, int, int>> authorData;  

   foreach (var paper in Papers.Where(p => p.Year >= startYear && p.Year <= endYear))  
   {  
      authorData.Add(paper.PaperID,  
                     new Tuple<List<int>, int, int, int>(  
                     paper.CoAuthors, paper.PaperCategory, paper.VenueID, paper.Year)  
                    );  
   }  
   return authorData;  
}

问题是在添加paper.CoAuthors 时，因为它是List<int>，所以它不会正确填充在元组内的列表。

更新

列表Papers定义为：

public List<Paper> Papers { get; set; }  

而Paper.cs 类定义为：

public class Paper
{
   // Class constructor
   public Paper()
   { }

   public int PaperID { get; set; }
   public List<int> CoAuthors { get; set; }
   public int VenueID { get; set; }
   public int PaperCategory { get; set; }
   public int Year { get; set; }
}

将GetAuthorData() 用作：

Dictionary<int, Author.AuthorData> tauthorData = eAuthor.GetAuthorData(year, year + 1);
foreach( var kvauthor in tauthorData)
{
   tw.WriteLine("PaperID: {0}, CoAuthors: {1}, PaperCategory: {2}, Venue: {3}, Year: {4}",  
   kvauthor.Key, kvauthor.Value.CoAuthors, kvauthor.Value.PaperCategory,  
   kvauthor.Value.VenueID, kvauthor.Value.Year);
}              

所需输出

PaperID: 1, CoAuthorID: 23, PaperCategory: 6, VenueID: 3454, Year: 2016  
PaperID: 1, CoAuthorID: 24, PaperCategory: 6, VenueID: 3454, Year: 2016  
PaperID: 1, CoAuthorID: 25, PaperCategory: 6, VenueID: 3454, Year: 2016  
PaperID: 1, CoAuthorID: 26, PaperCategory: 6, VenueID: 3454, Year: 2016  
PaperID: 2, CoAuthorID: 27, PaperCategory: 7, VenueID: 3455, Year: 2016  
PaperID: 2, CoAuthorID: 28, PaperCategory: 7, VenueID: 3455, Year: 2016  
PaperID: 2, CoAuthorID: 29, PaperCategory: 7, VenueID: 3455, Year: 2016  

我们如何才能正确添加到CoAuthors 列表？

Answer 1

你需要初始化字典：

public Dictionary<int, AuthorData> GetAuthorData(int startYear, int endYear)
{
    var authorData = new Dictionary<int, AuthorData>();

    foreach (var paper in Papers.Where(p => p.Year >= startYear && p.Year <= endYear))
    {
        Console.WriteLine(paper.CoAuthors.Count.ToString());
        authorData.Add(paper.PaperID,
                        new AuthorData()
                        {
                            CoAuthors = paper.CoAuthors,
                            PaperCategory = paper.PaperCategory,
                            VenueID = paper.VenueID,
                            Year = paper.Year
                        });
        Console.WriteLine("After");
        Console.WriteLine(authorData.Last().Value.Count.ToString());
    }

    return authorData;
}

class AuthorData
{
       public List<int> CoAuthors { set; get; }
       public int PaperCategory { set; get; }
       public int VenueID { set; get; }
       public int Year { set; get; }
}

至于您的打印代码，您需要这样做：

Dictionary<int, Author.AuthorData> tauthorData = eAuthor.GetAuthorData(year, year + 1);
foreach (var kvauthor in tauthorData)
{
    foreach (var author in kvauthor.Value.CoAuthors)
    {
        tw.WriteLine("PaperID: {0}, CoAuthors: {1}, PaperCategory: {2}, Venue: {3}, Year: {4}",
        kvauthor.Key, author, kvauthor.Value.PaperCategory,
        kvauthor.Value.VenueID, kvauthor.Value.Year);
    }
}