class Program
{
static void Main(string[] args)
{
List<Book> books = new List<Book>
{
new Book
{
Name="C# in Depth",
Authors = new List<Author>
{
new Author
{
FirstName = "Jon", LastName="Skeet"
},
new Author
{
FirstName = "Jon", LastName="Skeet"
},
}
},
new Book
{
Name="LINQ in Action",
Authors = new List<Author>
{
new Author
{
FirstName = "Fabrice", LastName="Marguerie"
},
new Author
{
FirstName = "Steve", LastName="Eichert"
},
new Author
{
FirstName = "Jim", LastName="Wooley"
},
}
},
};
var temp = books.SelectMany(book => book.Authors).Distinct();
foreach (var author in temp)
{
Console.WriteLine(author.FirstName + " " + author.LastName);
}
Console.Read();
}
}
public class Book
{
public string Name { get; set; }
public List<Author> Authors { get; set; }
}
public class Author
{
public string FirstName { get; set; }
public string LastName { get; set; }
public override bool Equals(object obj)
{
return true;
//if (obj.GetType() != typeof(Author)) return false;
//else return ((Author)obj).FirstName == this.FirstName && ((Author)obj).FirstName == this.LastName;
}
}
Dies basiert auf einem Beispiel in "LINQ in Action". Listing 4.16.
Dies druckt Jon Skeet zweimal. Warum? Ich habe sogar versucht, die Equals-Methode in der Author-Klasse zu überschreiben. Trotzdem scheint Distinct nicht zu funktionieren. Was vermisse ich?
Edit: Ich habe auch == und! = Operatorüberladung hinzugefügt. Immer noch keine Hilfe.
public static bool operator ==(Author a, Author b)
{
return true;
}
public static bool operator !=(Author a, Author b)
{
return false;
}