public static void ObtenerEmpresas()
{
IEnumerable <Empleado> query = from empleado in empleados
join empresa in empresas on empleado.EmpresaId equals empresa.Id
where empresa.Nombre == "Facebook"
select empleado;
Console.WriteLine("Los siguientes empleados trabajan en Facebook");
LinqExample <Empleado> .PrintDatosObjetos(query);
}
static void Main(string[] args)
{
int[] source = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
LinqExample <int> .FindEvenNumbers(source);
empresas = new List <Empresa>
{
new Empresa {
Id = 1, Nombre = "Google"
},
new Empresa {
Id = 2, Nombre = "Facebook"
}
};
empleados = new List <Empleado>
{
new Empleado {
Id = 1, Cargo = "Programador", EmpresaId = 1, Nombre = "Jorge", Salario = 1200
},
new Empleado {
Id = 2, Cargo = "CEO", EmpresaId = 1, Nombre = "Joel", Salario = 1200
},
new Empleado {
Id = 3, Cargo = "Analista", EmpresaId = 2, Nombre = "Kate", Salario = 1200
},
new Empleado {
Id = 4, Cargo = "Administrador", EmpresaId = 2, Nombre = "Luis", Salario = 1200
},
new Empleado {
Id = 5, Cargo = "Programador Senior", EmpresaId = 1, Nombre = "Emely", Salario = 1200
}
};
//TestEmpresa();
//EmpleadosOrdenados();
ObtenerEmpresas();
}
private static void LinqExample()
{
LinqExample myLinq = new LinqExample();
myLinq.ShowmeLinq();
}
private static void MyLinqSample()
{
LinqExample myLinq = new LinqExample();
myLinq.ShowMeLinq();
}
public static void EmpleadosOrdenados()
{
IEnumerable <Empleado> empleadosOrdenados = from empleado in empleados orderby empleado.Nombre descending select empleado;
LinqExample <Empleado> .PrintDatosObjetos(empleadosOrdenados);
}
public static void TestEmpresa()
{
IEnumerable <Empleado> query = from empleado in empleados where empleado.Cargo == "CEO" select empleado;
LinqExample <Empleado> .PrintDatosObjetos(query);
}
// This is basically a runner class, runs various classes implemented.
public static void Main(string[] args)
{
//var datalist = new StoreData<int>();
//datalist.Add(1);
//datalist.Add(2);
//datalist.Add(3);
//datalist.Add(4);
//datalist.Add(5);
//foreach (var item in datalist)
//{
// Console.WriteLine(item);
//}
//var datalist2 = new StoreData<string>();
//datalist2.Add("If ");
//datalist2.Add("Only ");
//datalist2.Add("I ");
//datalist2.Add("Could ");
//datalist2.Add("***.");
//foreach (var item in datalist2)
//{
// Console.Write(item);
//}
//Console.ReadLine();
A dataA = new A()
{
Data1 = "Hello", Data2 = "World"
};
// Assigning like this does a "shallow copy".
A dataB = dataA;
dataB.Data1 = "Goodbye";
dataB.Data2 = "City";
A dataBDistinct = new A(dataA);
// dataBDistinct should not be affected by changes made to dataA
dataA.Data1 = "Hello";
dataA.Data2 = "World";
StructExample someStruct = new StructExample();
StructExample someOtherStruct = new StructExample(1, 2);
//FileInfo fi = new FileInfo("ads");
//fi.Attributes = FileAttributes.ReadOnly | FileAttributes.ReadOnly;
Type predefineAttribute = typeof(AttributeUsageAttribute);
Type conditionalAttr = typeof(ConditionalAttribute);
foreach (Attribute attr in predefineAttribute.GetCustomAttributes(false))
{
Console.WriteLine(attr.ToString());
}
foreach (PropertyInfo poperty in predefineAttribute.GetProperties())
{
Console.WriteLine(poperty.ToString());
}
SomeObsoleteMethod();
IMyInterfaceCompression compression = new ZipCompression();
compression.Compress("", null);
compression = new RarCompression();
compression.Compress("", null);
Console.WriteLine("***************Async****************");
TestAsync();
// Console.WriteLine("***************Async****************");
Console.WriteLine("***************LINQ EXAMPLE ****************");
LinqExample db = new LinqExample();
var customers = from cust in db.Customers
select cust;
db.AddCustomer(new Customer()
{
Name = "NitinAr", Designation = "Technical Fellow", City = "Seattle"
});
foreach (Customer cst in customers)
{
Console.Write(cst.Name + ", ");
}
Console.WriteLine();
Console.WriteLine("***************LINQ EXAMPLE ****************");
Console.WriteLine("*************** DELEGATES, LAMBDAS ****************");
Func <int, int, bool> comparisonHandler = LessThan;
comparisonHandler = (a, b) => a < b;
comparisonHandler = delegate(int a, int b)
{
return(a < b);
};
Console.WriteLine("***************DELEGATES, LAMBDAS****************");
Console.WriteLine("***************vs EXPRESSIONS****************");
// Expression tree is a collection of Data and by iterating over data, it is possible to convert
// data to another type.
// Look at the different in calling ToString() on Func<> v/s Expression<>.
Expression <Func <int, int, bool> > comparisonHandlerExpression;
comparisonHandlerExpression = (x, y) => x < y;
Console.WriteLine(comparisonHandler.ToString());
Console.WriteLine(comparisonHandlerExpression.ToString());
Console.WriteLine(comparisonHandlerExpression.Body.ToString());
Console.WriteLine("***************vs EXPRESSIONS****************");
CloseOverMe closeOverMe = new CloseOverMe();
Func <int, int> incrementer = closeOverMe.GetFuncIncrementer();
Console.WriteLine(incrementer(3));
Console.WriteLine(incrementer(4));
Console.ReadLine();
}
static void Main(string[] args)
{
// Make sure the caller supplied a host name.
if (args.Length == 0 || args[0].Length == 0)
{
// Print a message and exit.
Console.WriteLine("You must specify the name of a host computer.");
return;
}
// Start the asynchronous request for DNS information.
IAsyncResult result = Dns.BeginGetHostEntry(args[0], null, null);
Console.WriteLine("Processing request for information...");
// Wait until the operation completes.
result.AsyncWaitHandle.WaitOne();
// The operation completed. Process the results.
try
{
// Get the results.
IPHostEntry host = Dns.EndGetHostEntry(result);
string[] aliases = host.Aliases;
IPAddress[] addresses = host.AddressList;
if (aliases.Length > 0)
{
Console.WriteLine("Aliases");
for (int i = 0; i < aliases.Length; i++)
{
Console.WriteLine("{0}", aliases[i]);
}
}
if (addresses.Length > 0)
{
Console.WriteLine("Addresses");
for (int i = 0; i < addresses.Length; i++)
{
Console.WriteLine("{0}", addresses[i].ToString());
}
}
}
catch (SocketException e)
{
Console.WriteLine("Exception occurred while processing the request: {0}",
e.Message);
}
Console.ReadLine();
// Linq
LinqExample ex = new LinqExample();
//ex.LinqConsole();
student_a entity1 = new student_a();
#region 字段属性，抽象方法，虚方法
//entity1.Test(); // 普通方法
//entity1.Abstract_Test(); // 抽象方法
//entity1.Abstract_Test1(); // 抽象方法
//entity1.Virtual_Test();// 虚方法
//entity1.Virtual_Test1();// 重写虚方法
// entity1.Name = "北京欢迎你";
// Console.WriteLine(entity1.Name);
//entity1.setAge(11);
//Console.WriteLine(entity1.getAge().ToString());
#endregion
#region 委托
//delegate_test dt = new delegate_test();
//dt.main();
#endregion
#region 泛型
#region ArrayList
//System.Collections.ArrayList list = new System.Collections.ArrayList();
//// Add an integer to the list.
//list.Add(3);
//// Add a string to the list. This will compile, but may cause an error later.
//list.Add("It is raining in Redmond.");
//int t = 0;
//// This causes an InvalidCastException to be returned.
//foreach (int x in list)
//{
// t += x;
//}
//List<int> listtt = new List<int> {1,2,3,4,5 };
#endregion
#region 参数委托约束
if (1 > 3)
{
var map = Test2.EnumNameValues <RainBow>();
foreach (var pair in map)
{
Console.WriteLine($"{pair.Key}:\t{pair.Value}");
}
}
#endregion
#region 泛型接口
if (1 > 3)
{
//Person is the type argument.
SortedList <Person> list = new SortedList <Person>();
//Create name and age values to initialize Person objects.
string[] names = new string[] { "a", "b", "c" };
int[] ages = new int[] { 1, 2, 3 };
//Populate the list.
for (int x = 0; x < 3; x++)
{
list.AddHead(new Person(names[x], ages[x]));
}
//Print out unsorted list.
foreach (Person p in list)
{
System.Console.WriteLine(p.ToString());
}
System.Console.WriteLine("Done with unsorted list");
//Sort the list.
list.BubbleSort();
//Print out sorted list.
foreach (Person p in list)
{
System.Console.WriteLine(p.ToString());
}
System.Console.WriteLine("Done with sorted list");
}
#endregion
#endregion
#region 元组
if (1 > 3)
{
var ToString = "This is some text";
var one = 1;
var Item1 = 5;
var projections = (ToString, one, Item1);
// Accessing the first field:
Console.WriteLine(projections.Item1);
//Console.WriteLine(projections.ToStrings);
// There is no semantic name 'ToString'
// Accessing the second field:
Console.WriteLine(projections.one);
Console.WriteLine(projections.Item2);
// Accessing the third field:
Console.WriteLine(projections.Item3);
// There is no semantic name 'Item`.
var pt1 = (X : 3, Y : 0);
var pt2 = (X : 3, Y : 4);
var xCoords = (pt1.X, pt2.X);
// There are no semantic names for the fields
// of xCoords.
// Accessing the first field:
Console.WriteLine(xCoords.Item1);
// Accessing the second field:
Console.WriteLine(xCoords.Item2);
}
if (1 > 3)
{
// The 'arity' and 'shape' of all these tuples are compatible.
// The only difference is the field names being used.
var unnamed = (42, "The meaning of life");
var anonymous = (16, "a perfect square");
var named = (Answer : 42, Message : "The meaning of life");
var differentNamed = (SecretConstant : 42, Label : "The meaning of life 123456");
unnamed = named;
// Console.WriteLine($"{unnamed.Item1}, {unnamed.Message}");
named = unnamed;
// 'named' still has fields that can be referred to
// as 'answer', and 'message':
Console.WriteLine($"{named.Answer}, {named.Message}");
// unnamed to unnamed:
anonymous = unnamed;
// named tuples.
named = differentNamed;
// The field names are not assigned. 'named' still has
// fields that can be referred to as 'answer' and 'message':
Console.WriteLine($"{named.Answer}, {named.Message}");
(long, string)conversion = named;
Console.WriteLine($"{conversion.Item1}, {conversion.Item2}");
}
#endregion
#region 运算符
if (1 > 3)
{
string[] arrNum = { "zero", "one", "two", "three", "four", "five", "six", "seven" };
var shortDig = arrNum.Where((a, index) => a.Length < index);
foreach (var sd in shortDig)
{
Console.WriteLine(sd);
}
}
#endregion
#region 迭代器
if (1 > 3)
{
DaysOfTheWeek week = new DaysOfTheWeek();
foreach (string day in week)
{
Console.WriteLine(day + " _ ");
}
}
#endregion
Console.ReadLine();
}
static void Main(string[] args)
{
LinqExample.LambdaExpressionGenericUsefulMethods();
Console.ReadLine();
}
