Csharp/CSharp Tutorial/LINQ/Anonymous
Содержание
- 1 Anonymous Method
- 2 Anonymous Type
- 3 Anonymous Type In Array
- 4 Anonymous Types
- 5 Array of anonymous types
- 6 Construct instance for nested class
- 7 Create new object from query
- 8 Implicit Local Variables with Anonymous Types
- 9 Return From Anonymous Method
- 10 Simple Anonymous Methods for calculating the mean value
- 11 Simple Anonymous Methods for printing out reverse numbers
- 12 Simple Anonymous Methods for printing the square root
- 13 Using Anonymous Methods with Find
Anonymous Method
<source lang="csharp">using System; using System.ruponentModel;
class MainClass
{
static void Main()
{
Func<string, int> returnLength = delegate(string text) { return text.Length; };
Console.WriteLine(returnLength("Hello"));
}
}</source>
Anonymous Type
<source lang="csharp">using System; using System.ruponentModel;
class MainClass
{
static void Main()
{
var tom = new { Name = "Tom", Age = 4 };
var holly = new { Name = "Holly", Age = 31 };
var jon = new { Name = "Jon", Age = 31 };
Console.WriteLine("{0} is {1} years old", jon.Name, jon.Age);
}
}</source>
Anonymous Type In Array
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.ruponentModel;
class AnonymousTypeInArray
{
static void Main()
{
var family = new[]
{
new { Name = "H", Age = 31 },
new { Name = "R", Age = 1 },
new { Name = "W", Age = 1 }
};
int totalAge = 0;
foreach (var person in family)
{
totalAge += person.Age;
}
Console.WriteLine("Total age: {0}", totalAge);
}
}</source>
Anonymous Types
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.ruponentModel;
class AnonymousTypes
{
static void Main()
{
var jon = new { Name = "Jon", Age = 31 };
var tom = new { Name = "Tom", Age = 4 };
Console.WriteLine("{0} is {1}", jon.Name, jon.Age);
Console.WriteLine("{0} is {1}", tom.Name, tom.Age);
}
}</source>
Array of anonymous types
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; class Program {
static void Main(string[] args)
{
var curries = new[]
{
new { M = "A", S= "C", A = 5 },
new { M = "B", S= "B", A= 5 },
new { M = "C", S= "A", A= 5 }
};
Console.WriteLine(curries[0].ToString());
Console.WriteLine(curries[0].GetHashCode());
Console.WriteLine(curries[1].GetHashCode());
Console.WriteLine(curries[2].GetHashCode());
Console.WriteLine(curries[0].Equals(curries[1]));
Console.WriteLine(curries[0].Equals(curries[2]));
Console.WriteLine(curries[0] == curries[1]);
Console.WriteLine(curries[0] == curries[2]);
}
}</source>
Construct instance for nested class
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text;
class Employee
{
public string Name { get; set; }
public decimal Salary { get; set; }
}
class Department
{
public string Name { get; set; }
List<Employee> employees = new List<Employee>();
public IList<Employee> Employees
{
get { return employees; }
}
}
class Company
{
public string Name { get; set; }
List<Department> departments = new List<Department>();
public IList<Department> Departments
{
get { return departments; }
}
}
class SalaryReport
{
static void Main()
{
var company = new Company
{
Name = "A",
Departments =
{
new Department
{
Name = "Development",
Employees =
{
new Employee { Name = "T", Salary = 75000m },
new Employee { Name = "D", Salary = 45000m },
new Employee { Name = "M", Salary = 150000m }
}
},
new Department
{
Name = "Marketing",
Employees =
{
new Employee { Name = "Z", Salary = 200000m },
new Employee { Name = "X", Salary = 120000m }
}
}
}
};
var query = company.Departments
.Select(dept => new { dept.Name, Cost = dept.Employees.Sum(person => person.Salary) })
.OrderByDescending(deptWithCost => deptWithCost.Cost);
foreach (var item in query)
{
Console.WriteLine(item);
}
}
}</source>
Create new object from query
<source lang="csharp">using System; using System.Collections.Generic; using System.Text; using System.Xml.Linq; using System.Linq;
class Car
{
public string PetName;
public string Color;
public int Speed;
public string Make;
public override string ToString()
{
return string.Format("Make={0}, Color={1}, Speed={2}, PetName={3}",Make, Color, Speed, PetName);
}
}
class Program
{
static void Main(string[] args)
{
Car[] myCars = new []{
new Car{ PetName = "A", Color = "Silver", Speed = 100, Make = "BMW"},
new Car{ PetName = "B", Color = "Black", Speed = 55, Make = "VW"},
new Car{ PetName = "C", Color = "White", Speed = 43, Make = "Ford"}
};
var makesColors = from c in myCars select new {c.Make, c.Color};
foreach (var o in makesColors)
{
Console.WriteLine(o.ToString());
}
}
}</source>
Implicit Local Variables with Anonymous Types
<source lang="csharp">class Program {
static void Main()
{
var patent1 =new { Title = "A",
YearOfPublication = "1984" };
var patent2 =new { Title = "B",
YearOfPublication = "1977" };
System.Console.WriteLine("{0} ({1})",patent1.Title, patent1.YearOfPublication);
System.Console.WriteLine("{0} ({1})",patent2.Title, patent1.YearOfPublication);
}
}</source>
Return From Anonymous Method
<source lang="csharp">using System; using System.ruponentModel;
class ReturnFromAnonymousMethod
{
static void Main()
{
Predicate<int> isEven = delegate(int x)
{ return x % 2 == 0; };
Console.WriteLine(isEven(1));
Console.WriteLine(isEven(4));
}
}</source>
Simple Anonymous Methods for calculating the mean value
<source lang="csharp">using System; using System.Collections.Generic; using System.ruponentModel;
class MainClass
{
static void Main()
{
Action<IList<double>> printMean = delegate(IList<double> numbers)
{
double total = 0;
foreach (double value in numbers)
{
total += value;
}
Console.WriteLine(total / numbers.Count);
};
double[] samples = { 1.5, 2.5, 3, 4.5 };
printMean(samples);
}
}</source>
Simple Anonymous Methods for printing out reverse numbers
<source lang="csharp">using System; using System.Collections.Generic; using System.ruponentModel;
class MainClass
{
static void Main()
{
Action<string> printReverse = delegate(string text)
{
char[] chars = text.ToCharArray();
Array.Reverse(chars);
Console.WriteLine(new string(chars));
};
printReverse("Hello world");
}
}</source>
Simple Anonymous Methods for printing the square root
<source lang="csharp">using System; using System.Collections.Generic; using System.ruponentModel;
class MainClass
{
static void Main()
{
Action<int> printRoot = delegate(int number)
{
Console.WriteLine(Math.Sqrt(number));
};
printRoot(2);
}
}</source>
Using Anonymous Methods with Find
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Linq.Expressions; using System.Xml.Linq;
class Program
{
static void Main(string[] args)
{
List<string> myList1 = new List<string>();
myList1.Add("A");
myList1.Add("B");
myList1.Add("C");
myList1.Add("D");
string vanilla1 = myList1.Find(delegate(string icecream)
{
return icecream.Equals("B");
});
Console.WriteLine(vanilla1);
}
}</source>
