SortVersion Class

Definition

Namespace:

System.Globalization

Assembly:

System.Runtime.dll

Source:

SortVersion.cs

Provides information about the version of Unicode used to compare and order strings.

public ref class SortVersion sealed : IEquatable<System::Globalization::SortVersion ^>

public sealed class SortVersion : IEquatable<System.Globalization.SortVersion>

type SortVersion = class
    interface IEquatable<SortVersion>

Public NotInheritable Class SortVersion
Implements IEquatable(Of SortVersion)

Inheritance

Object

SortVersion

Implements

IEquatable<SortVersion>

Examples

The following example contains a portion of the source code from an application that uses the SortVersion class to ensure that the native names of RegionInfo objects are ordered appropriately for the current system and current culture. It uses the BinaryReader and BinaryWriter objects to store and retrieve ordered data from a data file named Regions.dat rather than retrieving and ordering data each time the application is run. The example first checks to determine whether the data file exists. If it does not, it creates the data and sets the reindex flag, which indicates that the data must be resorted and saved again. Otherwise, it retrieves the data and compares the saved SortVersion object with the SortVersion object for the current culture on the current system. If they are not equal, or if the reindex flag had been set previously, it resorts to the RegionInfo data.

using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Text;

public class Example : IComparer
{
   private const string FILENAME = @".\Regions.dat";

   private struct Region
   {
      internal Region(string id, string name)
      {
         this.Id = id;
         this.NativeName = name;
      }

      public string Id;
      public string NativeName;

      public override string ToString()
      {
         return this.NativeName;
      }
   }

   public static void Main()
   {
      bool reindex = false;

      Region[] regions;
      SortVersion ver = null;

      // If the data has not been saved, create it.
      if (! File.Exists(FILENAME)) {
         regions = GenerateData();
         ver = CultureInfo.CurrentCulture.CompareInfo.Version;
         reindex = true;
      }
      // Retrieve the existing data.
      else {
         regions = RestoreData(out ver);
      }

      // Determine whether the current ordering is valid; if not, reorder.
      if (reindex || ver != CultureInfo.CurrentCulture.CompareInfo.Version) {
         Array.Sort(regions, new Example());
         // Save newly reordered data.
         SaveData(regions);
      }

      // Continue with application...
   }

   private static Region[] GenerateData()
   {
      List<Region> regions = new List<Region>();

      foreach (var culture in CultureInfo.GetCultures(CultureTypes.AllCultures)) {
         if (culture.IsNeutralCulture | culture.Equals(CultureInfo.InvariantCulture))
            continue;

         RegionInfo region = new RegionInfo(culture.Name);
         regions.Add(new Region(region.Name, region.NativeName));
      }
      return regions.ToArray();
   }

   private static Region[] RestoreData(out SortVersion ver)
   {
      List<Region> regions = new List<Region>();

      BinaryReader rdr = new BinaryReader(File.Open(FILENAME, FileMode.Open));

      int sortVer = rdr.ReadInt32();
      Guid sortId = Guid.Parse(rdr.ReadString());
      ver = new SortVersion(sortVer, sortId);

      string id, name;
      while (rdr.PeekChar() != -1) {
         id = rdr.ReadString();
         name = rdr.ReadString();
         regions.Add(new Region(id, name));
      }
      return regions.ToArray();
   }

   private static void SaveData(Region[] regions)
   {
      SortVersion ver = CultureInfo.CurrentCulture.CompareInfo.Version;

      BinaryWriter wrtr = new BinaryWriter(File.Open(FILENAME, FileMode.Create));
      wrtr.Write(ver.FullVersion);
      wrtr.Write(ver.SortId.ToString());

      foreach (var region in regions) {
         wrtr.Write(region.Id);
         wrtr.Write(region.NativeName);
      }
      wrtr.Close();
   }

   public int Compare(object o1, object o2)
   {
        // Assume that all casts succeed.
        Region r1 = (Region) o1;
        Region r2 = (Region) o2;

        return String.Compare(r1.NativeName, r2.NativeName,
                              StringComparison.CurrentCulture);
   }
}

Imports System.Collections
Imports System.Collections.Generic
Imports System.Globalization
Imports System.IO
Imports System.Text

Public Class Example : Implements IComparer
   Private Const FILENAME As String = ".\Regions.dat"
   
   Private Structure Region
      Friend Sub New(id As String, name As String)
         Me.Id = id
         Me.NativeName = name
      End Sub
      
      Dim Id As String
      Dim NativeName As String
      
      Public Overrides Function ToString() As String
         Return Me.NativeName
      End Function
   End Structure
   
   Public Shared Sub Main()
      Dim reindex As Boolean = False
      
      Dim regions() As Region
      Dim ver As SortVersion = Nothing

      ' If the data has not been saved, create it.
      If Not File.Exists(FILENAME) Then 
         regions = GenerateData()
         ver = CultureInfo.CurrentCulture.CompareInfo.Version  
         reindex = True
      ' Retrieve the existing data.
      Else
         regions = RestoreData(ver)
      End If

      ' Determine whether the current ordering is valid; if not, reorder.
      If reindex OrElse ver <> CultureInfo.CurrentCulture.CompareInfo.Version Then 
         Array.Sort(regions, New Example())      
         ' Save newly reordered data.
         SaveData(regions)
      End If
      
      ' Continue with application...
   End Sub

   Private Shared Function GenerateData() As Region()
      Dim regions As New List(Of Region)()

      For Each culture In CultureInfo.GetCultures(CultureTypes.AllCultures)
         If culture.IsNeutralCulture Or culture.Equals(CultureInfo.InvariantCulture) Then Continue For
            
         Dim region As New RegionInfo(culture.Name)
         regions.Add(New Region(region.Name, region.NativeName))
      Next
      Return regions.ToArray()
   End Function
   
   Private Shared Function RestoreData(ByRef ver As SortVersion) As Region()
      Dim regions As New List(Of Region)
      
      Dim rdr As New BinaryReader(File.Open(FILENAME, FileMode.Open))
      
      Dim sortVer As Integer = rdr.ReadInt32
      Dim sortId As Guid = Guid.Parse(rdr.ReadString())
      ver = New SortVersion(sortVer, sortId)
      
      Dim id As String, name As String
      Do While rdr.PeekChar <> -1
         id = rdr.ReadString()
         name = rdr.ReadString()
         regions.Add(New Region(id, name))      
      Loop
      Return regions.ToArray()
   End Function
   
   Private Shared Sub SaveData(regions As Region())
      Dim ver As SortVersion = CultureInfo.CurrentCulture.CompareInfo.Version

      Dim wrtr As New BinaryWriter(File.Open(FILENAME, FileMode.Create))
      wrtr.Write(ver.FullVersion) 
      wrtr.Write(ver.SortId.ToString()) 
      
      For Each region In regions
         wrtr.Write(region.Id)
         wrtr.Write(region.NativeName)
      Next
      wrtr.Close()
   End Sub

   Private Function SortByNativeName(o1 As Object, o2 As Object) As Integer _
           Implements IComparer.Compare
        ' Assume that all conversions succeed.
        Dim r1 As Region = CType(o1, Region)
        Dim r2 As Region = CType(o2, Region)
        
        Return String.Compare(r1.NativeName, r2.NativeName, 
                              StringComparison.CurrentCulture)         
   End Function
End Class

Remarks

For more information about this API, see Supplemental API remarks for SortVersion.

Constructors

SortVersion(Int32, Guid)

Creates a new instance of the SortVersion class.

Properties

FullVersion	Gets the full version number of the SortVersion object.
SortId	Gets a globally unique identifier for this SortVersion object.

Methods

Equals(Object)	Returns a value that indicates whether this SortVersion instance is equal to a specified object.
Equals(SortVersion)	Returns a value that indicates whether this SortVersion instance is equal to a specified SortVersion object.
GetHashCode()	Returns a hash code for this instance.
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

Operators

Equality(SortVersion, SortVersion)	Indicates whether two SortVersion instances are equal.
Inequality(SortVersion, SortVersion)	Indicates whether two SortVersion instances are not equal.

See also

• Version