123

//PaymentDto dto = new Payment() { Amount = 2.512M, User = "张三" };

//Payment payment = new PaymentDto() { User = "李四", AmountString = "1.364", Address = "无锡市新吴区" };

//List<Employee> empList = new List<Employee>();
//empList.Add(new Employee()
//{
// ID = 1,
// FName = "John",
// Age = 24,
// Sex = 'F'
//});

//empList.Add(new Employee()
//{
// ID = 1,
// FName = "John",
// Age = 23,
// Sex = 'M'
//});

//empList.Add(new Employee()
//{
// ID = 2,
// FName = "Mary",
// Age = 25,
// Sex = 'F'
//});

//empList.Add(new Employee()
//{
// ID = 3,
// FName = "Amber",
// Age = 23,
// Sex = 'M'
//});
//empList.Add(new Employee()
//{
// ID = 4,
// FName = "Kathy",
// Age = 25,
// Sex = 'M'
//});
//empList.Add(new Employee()
//{
// ID = 5,
// FName = "Lena",
// Age = 27,
// Sex = 'F'
//});

//empList.Add(new Employee()
//{
// ID = 6,
// FName = "Bill",
// Age = 28,
// Sex = 'M'
//});

//empList.Add(new Employee()
//{
// ID = 7,
// FName = "Celina",
// Age = 27,
// Sex = 'F'
//});
//empList.Add(new Employee()
//{
// ID = 8,
// FName = "John",
// Age = 28,
// Sex = 'M'
//});

//// 实现多key分组的扩展函数版本
//var sums = empList
// .GroupBy(x => new { x.ID, x.FName });
//foreach (var employee in sums)
//{
// Console.WriteLine(employee.Key+ ": " );
//}

//var a = new List<int> { 1,2,3};
//var b = new List<int>();

//b.AddRange(a);

//a.Clear();

//var d = b;

//var f = a;