Csharp/C Sharp/LINQ/OrderBy

Материал из .Net Framework эксперт
Версия от 11:38, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
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an array of string values sorted first by length, then sorted alphabetically, using a case-insentive comparison.

 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class CaseInsensitiveComparer : IComparer<string> {
    public int Compare(string x, string y) {
        return string.rupare(x, y, true);
    }
}
public class MainClass {
    public static void Main() {
        string[] words = { "a", "A", "b", "B", "C", "c" };
        var sortedWords =
            words.OrderBy(a => a.Length)
                    .ThenBy(a => a, new CaseInsensitiveComparer());
        Console.Write(sortedWords);
    }
}


First OrderBy Prototype

 
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
public class MainClass {
    public static void Main() {
        string[] presidents = {"ant", "arding", "arrison", "eyes", "over", "ackson"};
        IEnumerable<string> items = presidents.OrderBy(s => s.Length);
        foreach (string item in items)
            Console.WriteLine(item);
    }
}


OrderBy: prints an alphabetically sorted version of a string array

 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class MainClass {
    public static void Main() {
        string[] words = { "C", "a", "b" };
        var sortedWords =
            from w in words
            orderby w
            select w;
        Console.WriteLine("The sorted list of words:");
        foreach (var w in sortedWords) {
            Console.WriteLine(w);
        }
    }
}


OrderBy with customized Comparer

 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class CaseInsensitiveComparer : IComparer<string> {
    public int Compare(string x, string y) {
        return string.rupare(x, y, true);
    }
}
public class MainClass {
    public static void Main() {
        string[] words = { "a", "A", "b", "B", "C", "c" };
        var sortedWords = words.OrderBy(a => a, new CaseInsensitiveComparer());

    }
}


OrderBy with passing a lambda function

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class CaseInsensitiveComparer : IComparer<string> {
    public int Compare(string x, string y) {
        return string.rupare(x, y, true);
    }
}
public class MainClass {
    public static void Main() {
        string[] words = { "a", "A", "b", "B", "C", "c" };
        var sortedWords = words.OrderBy(a => a, new CaseInsensitiveComparer());

    }
}


products sorted alphabetically by the product name

 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class MainClass {
    public static void Main() {
        List<Product> products = GetProductList();
        var sortedProducts =
            from p in products
            orderby p.ProductName
            select p;
        Console.WriteLine(sortedProducts);
    }
    static List<Product> GetProductList() {
        List<Product> empTree = new List<Product>();
        empTree.Add(new Product { ProductName = "A", Category = "O", UnitPrice = 12, UnitsInStock = 5, Total = 36, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "B", Category = "O", UnitPrice = 2, UnitsInStock = 4, Total = 35, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "C", Category = "O", UnitPrice = 112, UnitsInStock = 3, Total = 34, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "D", Category = "O", UnitPrice = 112, UnitsInStock = 0, Total = 33, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "E", Category = "O", UnitPrice = 1112, UnitsInStock = 2, Total = 32, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "F", Category = "O", UnitPrice = 11112, UnitsInStock = 0, Total = 31, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        return empTree;
    }
}
class Product : IComparable<Product> {
    public string ProductName { get; set; }
    public string Category { get; set; }
    public int UnitPrice { get; set; }
    public int UnitsInStock { get; set; }
    public int Total { get; set; }
    public DateTime OrderDate { get; set; }
    public int Id { get; set; }
    public override string ToString() {
        return String.Format("Id: {0}, Name: {1} , Category: {3}", this.Id, this.ProductName, this.Category);
    }
    int IComparable<Product>.rupareTo(Product other) {
        if (other == null)
            return 1;
        if (this.Id > other.Id)
            return 1;
        if (this.Id < other.Id)
            return -1;
        return 0;
    }
}


products sorted by the number of units of each product that are in stock

 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class MainClass {
    public static void Main() {
        List<Product> products = GetProductList();
        var sortedProducts =
            from p in products
            orderby p.UnitsInStock descending
            select p;
        Console.Write(sortedProducts);
    }
    static List<Product> GetProductList() {
        List<Product> empTree = new List<Product>();
        empTree.Add(new Product { ProductName = "A", Category = "O", UnitPrice = 12, UnitsInStock = 5, Total = 36, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "B", Category = "O", UnitPrice = 2, UnitsInStock = 4, Total = 35, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "C", Category = "O", UnitPrice = 112, UnitsInStock = 3, Total = 34, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "D", Category = "O", UnitPrice = 112, UnitsInStock = 0, Total = 33, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "E", Category = "O", UnitPrice = 1112, UnitsInStock = 2, Total = 32, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "F", Category = "O", UnitPrice = 11112, UnitsInStock = 0, Total = 31, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        return empTree;
    }
}
class Product : IComparable<Product> {
    public string ProductName { get; set; }
    public string Category { get; set; }
    public int UnitPrice { get; set; }
    public int UnitsInStock { get; set; }
    public int Total { get; set; }
    public DateTime OrderDate { get; set; }
    public int Id { get; set; }
    public override string ToString() {
        return String.Format("Id: {0}, Name: {1} , Category: {3}", this.Id, this.ProductName, this.Category);
    }
    int IComparable<Product>.rupareTo(Product other) {
        if (other == null)
            return 1;
        if (this.Id > other.Id)
            return 1;
        if (this.Id < other.Id)
            return -1;
        return 0;
    }
}


sorted alphabetically in descending order, using a case insensitive comparision.

 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class CaseInsensitiveComparer : IComparer<string> {
    public int Compare(string x, string y) {
        return string.rupare(x, y, true);
    }
}
public class MainClass {
    public static void Main() {
        string[] words = { "a", "A", "b", "B", "C", "c" };
        var sortedWords = words.OrderByDescending(a => a, new CaseInsensitiveComparer());
    }
}


string array sorted by the length each element

 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class MainClass {
    public static void Main() {
        string[] words = { "abc", "bcd", "def" };
        var sortedWords =
            from w in words
            orderby w.Length
            select w;
        Console.WriteLine("The sorted list of words (by length):");
        foreach (var w in sortedWords) {
            Console.WriteLine(w);
        }
    }
}


uses a compound orderby to sort a list of digits first by length of their name, and then alphabetically.

 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class MainClass {
    public static void Main() {
        string[] digits = { "zero", "one", "two", "three"};
        var sortedDigits =
            from d in digits
            orderby d.Length, d
            select d;
        Console.WriteLine("Sorted digits:");
        foreach (var d in sortedDigits) {
            Console.WriteLine(d);
        }
    }
}


uses a compound orderby to sort a list of products, first by category, and then by unit price, from highest to lowest.

 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class MainClass {
    public static void Main() {
        List<Product> products = GetProductList();
        var sortedProducts =
            from p in products
            orderby p.Category, p.UnitPrice descending select p;
        foreach (var s in sortedProducts) {
            Console.Write(s);
        }
    }
    static List<Product> GetProductList() {
        List<Product> empTree = new List<Product>();
        empTree.Add(new Product { ProductName = "A", Category = "O", UnitPrice = 12, UnitsInStock = 5, Total = 36, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "B", Category = "O", UnitPrice = 2, UnitsInStock = 4, Total = 35, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "C", Category = "O", UnitPrice = 112, UnitsInStock = 3, Total = 34, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "D", Category = "O", UnitPrice = 112, UnitsInStock = 0, Total = 33, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "E", Category = "O", UnitPrice = 1112, UnitsInStock = 2, Total = 32, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        empTree.Add(new Product { ProductName = "F", Category = "O", UnitPrice = 11112, UnitsInStock = 0, Total = 31, OrderDate = new DateTime(2005, 1, 1), Id = 1 });
        return empTree;
    }
}
class Product : IComparable<Product> {
    public string ProductName { get; set; }
    public string Category { get; set; }
    public int UnitPrice { get; set; }
    public int UnitsInStock { get; set; }
    public int Total { get; set; }
    public DateTime OrderDate { get; set; }
    public int Id { get; set; }
    public override string ToString() {
        return String.Format("Id: {0}, Name: {1} , Category: {3}", this.Id, this.ProductName, this.Category);
    }
    int IComparable<Product>.rupareTo(Product other) {
        if (other == null)
            return 1;
        if (this.Id > other.Id)
            return 1;
        if (this.Id < other.Id)
            return -1;
        return 0;
    }
}


Where with OrderBy

 
using System;
using System.Collections.Generic;
using System.Linq;
public class MainClass {
    public static void Main() {
        string[] names = { "J", "P", "G", "Pa" };
        IEnumerable<string> query = names.Where(n => n.Contains("a"))
                                         .OrderBy(n => n.Length)
                                         .Select(n => n.ToUpper());
    }
}