学步园

视频演示：http://u.115.com/file/f2f372f454

可以使用 LINQ 查询来创建包含多个输入序列的元素的输出序列。下面的示例演示如何组合两个内存中的数据结构，但组合来自 XML 或 SQL 或数据集源的数据时可应用相同的原则。假定下面两种类类型：
public class Student<br /> {<br /> public string FirstName { get; set; }<br /> public string LastName { get; set; }<br /> public int ID { get; set; }<br /> public string Street { get; set; }<br /> public string City { get; set; }<br /> public List<int> Scores;<br /> }</p> <p>public class Teacher<br /> {<br /> public string FirstName { get; set; }<br /> public string LastName { get; set; }<br /> public int ID { get; set; }<br /> public string City { get; set; }<br /> }

下面的示例演示该查询：
static void Main(string[] args)<br /> {<br /> // Create the first data source.<br /> List<Student> Students = new List<Student>()<br /> {<br /> new Student {FirstName="Svetlana",<br /> LastName="Omelchenko",<br /> ID=111,<br /> Street="123 Main Street",<br /> City="Seattle",<br /> Scores= new List<int> {97, 92, 81, 60}},<br /> new Student {FirstName="Claire",<br /> LastName="O’Donnell",<br /> ID=112,<br /> Street="124 Main Street",<br /> City="Redmond",<br /> Scores= new List<int> {75, 84, 91, 39}},<br /> new Student {FirstName="Sven",<br /> LastName="Mortensen",<br /> ID=113,<br /> Street="125 Main Street",<br /> City="Lake City",<br /> Scores= new List<int> {88, 94, 65, 91}},<br /> };</p> <p> // Create the second data source.<br /> List<Teacher> Teachers = new List<Teacher>()<br /> {<br /> new Teacher {FirstName="Ann", LastName="Beebe", ID=945, City = "Seattle"},<br /> new Teacher {FirstName="Alex", LastName="Robinson", ID=956, City = "Redmond"},<br /> new Teacher {FirstName="Michiyo", LastName="Sato", ID=972, City = "Tacoma"}<br /> };</p> <p> // Create the query.<br /> var PeopleInSeattle = (from student in Students<br /> where student.City == "Seattle"<br /> select student.LastName)<br /> .Concat (from teacher in Teachers<br /> where teacher.City == "Seattle"<br /> select teacher.LastName);</p> <p> Console.WriteLine("The following Students and Teachers live in Seattle:");</p> <p> // Execute the query.<br /> foreach (var Person in PeopleInSeattle)<br /> {<br /> Console.WriteLine(Person);<br /> }</p> <p> Console.WriteLine("Press any key to exit.");<br /> Console.ReadKey();</p> <p>}<br />