LINQ OrderBy : best search results at top of results list

Question

考虑需要按名字和姓氏搜索客户列表。我们希望让搜索词中匹配最多的客户对结果列表进行排序。

FirstName      LastName----------     ---------Foo            LaurieBar            JacksonJackson        BroLaurie         FooJackson        Laurie

string[] searchTerms = new string[] {"Jackson", "Laurie"};

//want to find those customers with first, last or BOTH names in the searchTerms
var matchingCusts = Customers
                       .Where(m => searchTerms.Contains(m.FirstName)
                               ||  searchTerms.Contains(m.LastName))
                       .ToList();

/* Want to sort for those results with BOTH FirstName and LastName 
   matching in the search terms. Those that match on both First and Last
   should  be at the top of the results, the rest who match on 
   one property should be below.
*/

 return matchingCusts.OrderBy(m=>m); 

期望排序:

Jackson        Laurie  (matches on both properties)
Foo            Laurie
Bar            Jackson
Jackson        Bro
Laurie         Foo

我如何使用 LINQ 和 OrderBy 实现此所需功能/ OrderByDescending ?

Answer 1

使用 Select与客户进行“匹配评估”，然后按以下顺序订购:

class Program
{
    static void Main(string[] args)
    {
        var Customers = new Customer[]
        {
            new Customer { FirstName = "Foo", LastName = "Laurie" },
            new Customer { FirstName = "Bar", LastName = "Jackson" },
            new Customer { FirstName = "Jackson", LastName = "Bro" },
            new Customer { FirstName = "Laurie", LastName = "Foo" },
            new Customer { FirstName = "Jackson", LastName = "Laurie" },
        };

        string[] searchTerms = new string[] { "Jackson", "Laurie" };

        //want to find those customers with first, last or BOTH names in the searchTerms 
        var matchingCusts = Customers
                               .Where(m => searchTerms.Contains(m.FirstName)
                                       || searchTerms.Contains(m.LastName))
                               .ToList();

        var result = matchingCusts.Select(x => new
            {
                Customer = x,
                MatchEvaluation = (searchTerms.Contains(x.FirstName) ? 1 : 0) + (searchTerms.Contains(x.LastName) ? 1 : 0),
            })
            .OrderByDescending(x => x.MatchEvaluation)
            .Select(x => x.Customer);

        foreach (var c in result)
        {
            Console.WriteLine(c.FirstName + " " + c.LastName);
        }

        Console.ReadKey();
    }

    public sealed class Customer
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
    }
}