в 15:31, 26 мая 2010

2010-05-26T15:31:18Z

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2010-05-26T11:38:50Z

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==A More Complex Example of the First SelectMany==

<source lang="csharp">
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
public class Employee {
public int id;
public string firstName;
public string lastName;
public static ArrayList GetEmployeesArrayList() {
ArrayList al = new ArrayList();
al.Add(new Employee { id = 1, firstName = "J", lastName = "R" });
al.Add(new Employee { id = 2, firstName = "W", lastName = "G" });
al.Add(new Employee { id = 3, firstName = "A", lastName = "H" });
al.Add(new Employee { id = 4, firstName = "D", lastName = "L" });
al.Add(new Employee { id = 101, firstName = "K", lastName = "F" });
return (al);
}
public static Employee[] GetEmployeesArray() {
return ((Employee[])GetEmployeesArrayList().ToArray());
}
}
public class EmployeeOptionEntry {
public int id;
public long optionsCount;
public DateTime dateAwarded;
public static EmployeeOptionEntry[] GetEmployeeOptionEntries() {
EmployeeOptionEntry[] empOptions = new EmployeeOptionEntry[] {
new EmployeeOptionEntry {
id = 1,
optionsCount = 2,
dateAwarded = DateTime.Parse("1999/12/31") },
new EmployeeOptionEntry {
id = 101,
optionsCount = 2,
dateAwarded = DateTime.Parse("1998/12/31") }
};
return (empOptions);
}
}

public class MainClass {
public static void Main() {
Employee[] employees = Employee.GetEmployeesArray();
EmployeeOptionEntry[] empOptions = EmployeeOptionEntry.GetEmployeeOptionEntries();
var employeeOptions = employees
.SelectMany(e => empOptions
.Where(eo => eo.id == e.id)
.Select(eo => new {
id = eo.id,
optionsCount = eo.optionsCount
}));
foreach (var item in employeeOptions)
Console.WriteLine(item);
}
}
</source>

==SelectMany Prototype==

<source lang="csharp">
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
public class MainClass {
public static void Main() {
string[] presidents = {"Ad", "Art", "Buch", "Bush", "Car", "land"};
IEnumerable<char> chars = presidents.SelectMany(p => p.ToArray());
foreach (char ch in chars)
Console.WriteLine(ch);
}
}
</source>

==SelectMany Prototype: with ? operator==

<source lang="csharp">
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
public class MainClass {
public static void Main() {
string[] presidents = {"A", "Art", "Buch", "Bush", "Carter", "land"};
IEnumerable<char> chars = presidents
.SelectMany((p, i) => i < 5 ? p.ToArray() : new char[] { });
foreach (char ch in chars)
Console.WriteLine(ch);
}
}
</source>

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Csharp/C Sharp/LINQ/SelectMany - История изменений

в 15:31, 26 мая 2010

Admin: 1 версия