c# - 可枚举连接 - 连接两个列表

Question

我有两个包含以下数据的列表（列表）：

清单一

James
Jack
Laura
Harry

清单二

Jeffery
Peters
Smith

是否可以使用 Enumerable Join 来执行以下操作：

James Jeffery
James Peters
James Smith
Jack Jeffery
Jack Peters
Jack Smith
Laura Jeffery
Laura Peters
Laura Smith
Harry Jeffery
Harry Peters
Harry Smith
Harry Jeffery

这是什么类型的Join？

Answer 1

这是一个交叉连接：

List<string> textLines1 = new List<string>() {
    "Kames", "Jack", "Laura", "Harry"
};
List<string> textLines2 = new List<string>() {
    "Jeffery", "Peters", "Smith"
};

var query = from t1 in textLines1
            from t2 in textLines2
            select string.Format("{0} {1}", t1, t2);

var results = query.ToList();

返回您所期望的。

也可以使用基于方法的查询来完成：

var query2 = textLines1.SelectMany(t1 => textLines2, (t1, t2) => string.Format("{0} {1}", t1, t2));

var results2 = query2.ToList();

Answer 2

在 Linq 中，它将是：

List<string> TabOne = new List<string>() { "Kames", "Jack", "Laura", "Harry" };
List<string> TabTwo = new List<string>() { "Jeffery", "Peters", "Smith" }; 

var combo = from p in TabOne
        from c in TabTwo
        select new
        {
            Name = p,
            SurName = c
        };

它被称为交叉连接。

Answer 3

var l1 = new []{ "James", "Jack", "Laura", "Harry" };
var l2 = new []{ "Jeffery", "Peters", "Smith" };

var result = from i1 in l1
             from i2 in l2
             select i1 + " " + i2;

Answer 4

这也被称为Cartesian ProductEric 有一篇关于它的博客文章。

Answer 5

您可以尝试这种方式：

var result = list1.SelectMany(i1 => list2.Select(i2 => i1 + " " + i2));

例子 ：

class Program
{
    public static void Main()
    {
        string[] list1 = new[] { "James", "Jack", "Laura", "Harry" };
        string[] list2 = new[] { "Jeffery", "Peters", "Smith" };
        var result = list1.SelectMany(i1 => list2.Select(i2 => i1 + " " + i2));

        foreach (string s in result)
        {
            Console.WriteLine(s);
        }
    }
}

应用输出：

James Jeffery
James Peters
James Smith
Jack Jeffery
Jack Peters
Jack Smith
Laura Jeffery
Laura Peters
Laura Smith
Harry Jeffery
Harry Peters
Harry Smith