Concat()方法附加两个相同类型的序列，并返回一个新序列（集合）。
IList<string> collection1 = new List<string>() { "One", "Two", "Three" };
IList<string> collection2 = new List<string>() { "Five", "Six"};
var collection3 = collection1.Concat(collection2);
foreach (string str in collection3)
Console.WriteLine(str);One Two Three Five Six
IList<int> collection1 = new List<int>() { 1, 2, 3 };
IList<int> collection2 = new List<int>() { 4, 5, 6 };
var collection3 = collection1.Concat(collection2);
foreach (int i in collection3)
Console.WriteLine(i);1
2
3
4
5
6
C＃或VB.Net中的查询语法不支持Concat运算符。