class Program
{
static void Main(string[] args)
{
List<EmployeeLocalRegister> lclEmployees = new List<EmployeeLocalRegister>() {
new EmployeeLocalRegister(){Name = "A", Phone= "A1"},
new EmployeeLocalRegister(){Name = "B", Phone= "B1"},
new EmployeeLocalRegister(){Name = "A", Phone= "A2"},
new EmployeeLocalRegister(){Name = "B", Phone= "B2"},
new EmployeeLocalRegister(){Name = "B", Phone= "B3"},
new EmployeeLocalRegister(){Name = "C", Phone= "C1"}};
List<EmployeeTelDir> telDir = new List<EmployeeTelDir>();
var queryEmployeeLocalRegisterByName =
from empl in lclEmployees
group empl by empl.Name;
foreach (var employeeGroup in queryEmployeeLocalRegisterByName)
{
Console.WriteLine(employeeGroup.Key);
List<string> phone = new List<string>();
foreach (EmployeeLocalRegister employee in employeeGroup)
{
Console.WriteLine(" {0}", employee.Phone);
phone.Add(employee.Phone);
}
telDir.Add(new EmployeeTelDir() { Name = employeeGroup.Key, Phone = phone });
}
Console.ReadKey();
}
}
public class EmployeeLocalRegister
{
public string Name;
public string Phone;
}
public class EmployeeTelDir
{
public string Name;
public List<string> Phone;
}
}
我使用上面的代码转换List< EmployeeLocalRegister>列出< EmployeeTelDir>.这是唯一的优化方式吗?
我可以编写更简单的代码来进行List< EmployeeLocalRegister>的来回转换吗?列出< EmployeeTelDir>反之亦然使用Linq查询?
最佳答案 如果您不需要Console.WriteLine(…),您的代码可以使用LINQ进行汇总:
List<EmployeeTelDir> telDir = (from empl in lclEmployees
group empl by empl.Name into employeeGroup
select new EmployeeTelDir
{
Name = employeeGroup.Key,
Phone = (from employee in employeeGroup
select employee.Phone).ToList() // The ToList() is the Holy Grail of the LINQ queries
}).ToList();
对于倒置操作:
List<EmployeeLocalRegister> inverse = (from employeeTelDir in telDir
from phone in employeeTelDir.Phone // Doing 2 from ... in ... successively corresponds to the SelectMany() LINQ method
select new EmployeeLocalRegister
{
Name = employeeTelDir.Name,
Phone = phone
}).ToList();