Normalizzazione

Aggiornamento: novembre 2007

Alcuni caratteri Unicode hanno più rappresentazioni binarie equivalenti formate da set di caratteri Unicode combinati e/o compositi. La presenza di più rappresentazioni per un unico carattere rende più complesse determinate operazioni, quali la ricerca, l'ordinamento e l'associazione.

Nello standard Unicode viene definito un processo denominato normalizzazione che restituisce una rappresentazione binaria per qualsiasi rappresentazione binaria equivalente di un carattere. Per la normalizzazione è possibile utilizzare diversi algoritmi, denominati formati di normalizzazione, che obbediscono a regole diverse. In .NET Framework sono attualmente supportate le forme di normalizzazione Unicode C, D, KC e KD.

Nota:
Due stringhe normalizzate in base allo stesso formato di normalizzazione possono essere confrontate mediante un'operazione di confronto ordinale, ovvero un confronto binario carattere per carattere.

Per ulteriori informazioni sulle forme di normalizzazione supportate da .NET Framework, vedere NormalizationForm. Per ulteriori informazioni sulla normalizzazione, la scomposizione dei caratteri e l'equivalenza, vedere il documento Unicode Standard Annex #15, "Unicode Normalization Forms", sul sito Web Unicode (informazioni in lingua inglese).

Normalizzazione di una stringa

Mediante l'applicazione, utilizzare il metodo String.Normalize di un oggetto String per restituire una nuova stringa normalizzata per impostazione predefinita in base al formato di normalizzazione C. In alternativa è possibile utilizzare il metodo String.Normalize di un oggetto String specificando un valore NormalizationForm in modo da restituire una nuova stringa normalizzata specificamente in base al formato di normalizzazione C, D, KC o KD.

Verifica della normalizzazione di una stringa

Mediante l'applicazione, utilizzare il metodo String.IsNormalized di un oggetto String per determinare se il valore stringa dell'oggetto viene normalizzato in base al formato di normalizzazione C. In alternativa è possibile utilizzare il metodo String.IsNormalized di un oggetto String specificando un valore NormalizationForm particolare per determinare se il valore stringa dell'oggetto viene normalizzato specificamente in base al formato di normalizzazione C, D, KC o KD.

Esempio

Nell'esempio di codice riportato di seguito vengono illustrati i metodi IsNormalized e Normalize. Nell'esempio di codice viene verificato se una stringa originale è codificata in base a uno dei quattro formati di normalizzazione, viene creata una versione della stringa originale in ciascuno dei quattro formati, viene controllato se ciascuna stringa normalizzata è codificata nel formato desiderato e quindi viene visualizzato il punto di codice esadecimale di ciascun carattere di tutte le stringhe normalizzate.

' This example demonstrates the String.Normalize method
'                       and the String.IsNormalized method
Imports System
Imports System.Text
Imports Microsoft.VisualBasic

Class Sample
   Public Shared Sub Main()
      ' Character c; combining characters acute and cedilla; character 3/4
      Dim s1 = New [String](New Char() {ChrW(&H0063), ChrW(&H0301), ChrW(&H0327), ChrW(&H00BE)})
      Dim s2 As String = Nothing
      Dim divider = New [String]("-"c, 80)
      divider = [String].Concat(Environment.NewLine, divider, Environment.NewLine)

      Try
         Show("s1", s1)
         Console.WriteLine()
         Console.WriteLine("U+0063 = LATIN SMALL LETTER C")
         Console.WriteLine("U+0301 = COMBINING ACUTE ACCENT")
         Console.WriteLine("U+0327 = COMBINING CEDILLA")
         Console.WriteLine("U+00BE = VULGAR FRACTION THREE QUARTERS")

         Console.WriteLine(divider)

         Console.WriteLine("A1) Is s1 normalized to the default form (Form C)?: {0}", s1.IsNormalized())
         Console.WriteLine("A2) Is s1 normalized to Form C?:  {0}", s1.IsNormalized(NormalizationForm.FormC))
         Console.WriteLine("A3) Is s1 normalized to Form D?:  {0}", s1.IsNormalized(NormalizationForm.FormD))
         Console.WriteLine("A4) Is s1 normalized to Form KC?: {0}", s1.IsNormalized(NormalizationForm.FormKC))
         Console.WriteLine("A5) Is s1 normalized to Form KD?: {0}", s1.IsNormalized(NormalizationForm.FormKD))

         Console.WriteLine(divider)

         Console.WriteLine("Set string s2 to each normalized form of string s1.")
         Console.WriteLine()
         Console.WriteLine("U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE")
         Console.WriteLine("U+0033 = DIGIT THREE")
         Console.WriteLine("U+2044 = FRACTION SLASH")
         Console.WriteLine("U+0034 = DIGIT FOUR")
         Console.WriteLine(divider)

         s2 = s1.Normalize()
         Console.Write("B1) Is s2 normalized to the default form (Form C)?: ")
         Console.WriteLine(s2.IsNormalized())
         Show("s2", s2)
         Console.WriteLine()

         s2 = s1.Normalize(NormalizationForm.FormC)
         Console.Write("B2) Is s2 normalized to Form C?: ")
         Console.WriteLine(s2.IsNormalized(NormalizationForm.FormC))
         Show("s2", s2)
         Console.WriteLine()

         s2 = s1.Normalize(NormalizationForm.FormD)
         Console.Write("B3) Is s2 normalized to Form D?: ")
         Console.WriteLine(s2.IsNormalized(NormalizationForm.FormD))
         Show("s2", s2)
         Console.WriteLine()

         s2 = s1.Normalize(NormalizationForm.FormKC)
         Console.Write("B4) Is s2 normalized to Form KC?: ")
         Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKC))
         Show("s2", s2)
         Console.WriteLine()

         s2 = s1.Normalize(NormalizationForm.FormKD)
         Console.Write("B5) Is s2 normalized to Form KD?: ")
         Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKD))
         Show("s2", s2)
         Console.WriteLine()

      Catch e As Exception
         Console.WriteLine(e.Message)
      End Try
   End Sub 'Main

   Private Shared Sub Show(title As String, s As String)
      Console.Write("Characters in string {0} = ", title)
      Dim x As Char
      For Each x In  s.ToCharArray()
         Console.Write("{0:X4} ", AscW(x))
      Next x
      Console.WriteLine()
   End Sub 'Show
End Class 'Sample
'
'This example produces the following results:
'
'Characters in string s1 = 0063 0301 0327 00BE
'
'U+0063 = LATIN SMALL LETTER C
'U+0301 = COMBINING ACUTE ACCENT
'U+0327 = COMBINING CEDILLA
'U+00BE = VULGAR FRACTION THREE QUARTERS
'
'--------------------------------------------------------------------------------
'
'A1) Is s1 normalized to the default form (Form C)?: False
'A2) Is s1 normalized to Form C?:  False
'A3) Is s1 normalized to Form D?:  False
'A4) Is s1 normalized to Form KC?: False
'A5) Is s1 normalized to Form KD?: False
'
'--------------------------------------------------------------------------------
'
'Set string s2 to each normalized form of string s1.
'
'U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
'U+0033 = DIGIT THREE
'U+2044 = FRACTION SLASH
'U+0034 = DIGIT FOUR
'
'--------------------------------------------------------------------------------
'
'B1) Is s2 normalized to the default form (Form C)?: True
'Characters in string s2 = 1E09 00BE
'
'B2) Is s2 normalized to Form C?: True
'Characters in string s2 = 1E09 00BE
'
'B3) Is s2 normalized to Form D?: True
'Characters in string s2 = 0063 0327 0301 00BE
'
'B4) Is s2 normalized to Form KC?: True
'Characters in string s2 = 1E09 0033 2044 0034
'
'B5) Is s2 normalized to Form KD?: True
'Characters in string s2 = 0063 0327 0301 0033 2044 0034
'

// This example demonstrates the String.Normalize method
//                       and the String.IsNormalized method

using System;
using System.Text;

class Sample 
{
    public static void Main() 
    {
// Character c; combining characters acute and cedilla; character 3/4
    string s1 = new String( new char[] {'\u0063', '\u0301', '\u0327', '\u00BE'});
    string s2 = null;
    string divider = new String('-', 80);
    divider = String.Concat(Environment.NewLine, divider, Environment.NewLine);

    try 
    {
    Show("s1", s1);
    Console.WriteLine();
    Console.WriteLine("U+0063 = LATIN SMALL LETTER C");
    Console.WriteLine("U+0301 = COMBINING ACUTE ACCENT");
    Console.WriteLine("U+0327 = COMBINING CEDILLA");
    Console.WriteLine("U+00BE = VULGAR FRACTION THREE QUARTERS");
    Console.WriteLine(divider);

    Console.WriteLine("A1) Is s1 normalized to the default form (Form C)?: {0}", 
                                 s1.IsNormalized());
    Console.WriteLine("A2) Is s1 normalized to Form C?:  {0}", 
                                 s1.IsNormalized(NormalizationForm.FormC));
    Console.WriteLine("A3) Is s1 normalized to Form D?:  {0}", 
                                 s1.IsNormalized(NormalizationForm.FormD));
    Console.WriteLine("A4) Is s1 normalized to Form KC?: {0}", 
                                 s1.IsNormalized(NormalizationForm.FormKC));
    Console.WriteLine("A5) Is s1 normalized to Form KD?: {0}", 
                                 s1.IsNormalized(NormalizationForm.FormKD));

    Console.WriteLine(divider);

    Console.WriteLine("Set string s2 to each normalized form of string s1.");
    Console.WriteLine();
    Console.WriteLine("U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE");
    Console.WriteLine("U+0033 = DIGIT THREE");
    Console.WriteLine("U+2044 = FRACTION SLASH");
    Console.WriteLine("U+0034 = DIGIT FOUR");
    Console.WriteLine(divider);

    s2 = s1.Normalize();
    Console.Write("B1) Is s2 normalized to the default form (Form C)?: ");
    Console.WriteLine(s2.IsNormalized());
    Show("s2", s2);
    Console.WriteLine();

    s2 = s1.Normalize(NormalizationForm.FormC);
    Console.Write("B2) Is s2 normalized to Form C?: ");
    Console.WriteLine(s2.IsNormalized(NormalizationForm.FormC));
    Show("s2", s2);
    Console.WriteLine();

    s2 = s1.Normalize(NormalizationForm.FormD);
    Console.Write("B3) Is s2 normalized to Form D?: ");
    Console.WriteLine(s2.IsNormalized(NormalizationForm.FormD));
    Show("s2", s2);
    Console.WriteLine();

    s2 = s1.Normalize(NormalizationForm.FormKC);
    Console.Write("B4) Is s2 normalized to Form KC?: ");
    Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKC));
    Show("s2", s2);
    Console.WriteLine();

    s2 = s1.Normalize(NormalizationForm.FormKD);
    Console.Write("B5) Is s2 normalized to Form KD?: ");
    Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKD));
    Show("s2", s2);
    Console.WriteLine();
    }

    catch (Exception e) 
        {
        Console.WriteLine(e.Message);
        }
    }

    private static void Show(string title, string s)
    {
    Console.Write("Characters in string {0} = ", title);
    foreach(short x in s.ToCharArray())
        {
        Console.Write("{0:X4} ", x);
        }
    Console.WriteLine();
    }
}
/*
This example produces the following results:

Characters in string s1 = 0063 0301 0327 00BE

U+0063 = LATIN SMALL LETTER C
U+0301 = COMBINING ACUTE ACCENT
U+0327 = COMBINING CEDILLA
U+00BE = VULGAR FRACTION THREE QUARTERS

--------------------------------------------------------------------------------

A1) Is s1 normalized to the default form (Form C)?: False
A2) Is s1 normalized to Form C?:  False
A3) Is s1 normalized to Form D?:  False
A4) Is s1 normalized to Form KC?: False
A5) Is s1 normalized to Form KD?: False

--------------------------------------------------------------------------------

Set string s2 to each normalized form of string s1.

U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
U+0033 = DIGIT THREE
U+2044 = FRACTION SLASH
U+0034 = DIGIT FOUR

--------------------------------------------------------------------------------

B1) Is s2 normalized to the default form (Form C)?: True
Characters in string s2 = 1E09 00BE

B2) Is s2 normalized to Form C?: True
Characters in string s2 = 1E09 00BE

B3) Is s2 normalized to Form D?: True
Characters in string s2 = 0063 0327 0301 00BE

B4) Is s2 normalized to Form KC?: True
Characters in string s2 = 1E09 0033 2044 0034

B5) Is s2 normalized to Form KD?: True
Characters in string s2 = 0063 0327 0301 0033 2044 0034

*/

// This example demonstrates the String.Normalize method
//                       and the String.IsNormalized method
using namespace System;
using namespace System::Text;
void Show( String^ title, String^ s )
{
   Console::Write( "Characters in string {0} = ", title );
   System::Collections::IEnumerator^ myEnum = s->ToCharArray()->GetEnumerator();
   while ( myEnum->MoveNext() )
   {

      /*) * __try_cast < Char * > ( myEnum -> Current );*/
      int x;
      Console::Write( "{0:X4} ", x );
   }

   Console::WriteLine();
}

int main()
{

   // Character c; combining characters acute and cedilla; character 3/4
   array<Char>^temp0 = {L'c',L'\u0301',L'\u0327',L'\u00BE'};
   String^ s1 = gcnew String( temp0 );
   String^ s2 = nullptr;
   String^ divider = gcnew String( '-',80 );
   divider = String::Concat( Environment::NewLine, divider, Environment::NewLine );
   try
   {
      Show( "s1", s1 );
      Console::WriteLine();
      Console::WriteLine( "U+0063 = LATIN SMALL LETTER C" );
      Console::WriteLine( "U+0301 = COMBINING ACUTE ACCENT" );
      Console::WriteLine( "U+0327 = COMBINING CEDILLA" );
      Console::WriteLine( "U+00BE = VULGAR FRACTION THREE QUARTERS" );
      Console::WriteLine( divider );
      Console::WriteLine( "A1) Is s1 normalized to the default form (Form C)?: {0}", s1->IsNormalized() );
      Console::WriteLine( "A2) Is s1 normalized to Form C?:  {0}", s1->IsNormalized( NormalizationForm::FormC ) );
      Console::WriteLine( "A3) Is s1 normalized to Form D?:  {0}", s1->IsNormalized( NormalizationForm::FormD ) );
      Console::WriteLine( "A4) Is s1 normalized to Form KC?: {0}", s1->IsNormalized( NormalizationForm::FormKC ) );
      Console::WriteLine( "A5) Is s1 normalized to Form KD?: {0}", s1->IsNormalized( NormalizationForm::FormKD ) );
      Console::WriteLine( divider );
      Console::WriteLine( "Set string s2 to each normalized form of string s1." );
      Console::WriteLine();
      Console::WriteLine( "U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE" );
      Console::WriteLine( "U+0033 = DIGIT THREE" );
      Console::WriteLine( "U+2044 = FRACTION SLASH" );
      Console::WriteLine( "U+0034 = DIGIT FOUR" );
      Console::WriteLine( divider );
      s2 = s1->Normalize();
      Console::Write( "B1) Is s2 normalized to the default form (Form C)?: " );
      Console::WriteLine( s2->IsNormalized() );
      Show( "s2", s2 );
      Console::WriteLine();
      s2 = s1->Normalize( NormalizationForm::FormC );
      Console::Write( "B2) Is s2 normalized to Form C?: " );
      Console::WriteLine( s2->IsNormalized( NormalizationForm::FormC ) );
      Show( "s2", s2 );
      Console::WriteLine();
      s2 = s1->Normalize( NormalizationForm::FormD );
      Console::Write( "B3) Is s2 normalized to Form D?: " );
      Console::WriteLine( s2->IsNormalized( NormalizationForm::FormD ) );
      Show( "s2", s2 );
      Console::WriteLine();
      s2 = s1->Normalize( NormalizationForm::FormKC );
      Console::Write( "B4) Is s2 normalized to Form KC?: " );
      Console::WriteLine( s2->IsNormalized( NormalizationForm::FormKC ) );
      Show( "s2", s2 );
      Console::WriteLine();
      s2 = s1->Normalize( NormalizationForm::FormKD );
      Console::Write( "B5) Is s2 normalized to Form KD?: " );
      Console::WriteLine( s2->IsNormalized( NormalizationForm::FormKD ) );
      Show( "s2", s2 );
      Console::WriteLine();
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}

/*
This example produces the following results:

Characters in string s1 = 0063 0301 0327 00BE

U+0063 = LATIN SMALL LETTER C
U+0301 = COMBINING ACUTE ACCENT
U+0327 = COMBINING CEDILLA
U+00BE = VULGAR FRACTION THREE QUARTERS

--------------------------------------------------------------------------------

A1) Is s1 normalized to the default form (Form C)?: False
A2) Is s1 normalized to Form C?:  False
A3) Is s1 normalized to Form D?:  False
A4) Is s1 normalized to Form KC?: False
A5) Is s1 normalized to Form KD?: False

--------------------------------------------------------------------------------

Set string s2 to each normalized form of string s1.

U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
U+0033 = DIGIT THREE
U+2044 = FRACTION SLASH
U+0034 = DIGIT FOUR

--------------------------------------------------------------------------------

B1) Is s2 normalized to the default form (Form C)?: True
Characters in string s2 = 1E09 00BE

B2) Is s2 normalized to Form C?: True
Characters in string s2 = 1E09 00BE

B3) Is s2 normalized to Form D?: True
Characters in string s2 = 0063 0327 0301 00BE

B4) Is s2 normalized to Form KC?: True
Characters in string s2 = 1E09 0033 2044 0034

B5) Is s2 normalized to Form KD?: True
Characters in string s2 = 0063 0327 0301 0033 2044 0034

*/

// This example demonstrates the String.Normalize method
//                       and the String.IsNormalized method
import System.*;
import System.Text.*;

class Sample
{
    public static void main(String[] args)
    {
        // Character c; combining characters acute and cedilla; character 3/4
        String s1 = new String(new char[] { '\u0063', '\u0301', '\u0327', 
            '\u00BE' });
        String s2 = null;
        String divider = new String('-', 80);
        divider = String.Concat(Environment.get_NewLine(), divider, 
            Environment.get_NewLine());

        try {
            Show("s1", s1);
            Console.WriteLine();
            Console.WriteLine("U+0063 = LATIN SMALL LETTER C");
            Console.WriteLine("U+0301 = COMBINING ACUTE ACCENT");
            Console.WriteLine("U+0327 = COMBINING CEDILLA");
            Console.WriteLine("U+00BE = VULGAR FRACTION THREE QUARTERS");
            Console.WriteLine(divider);

            Console.WriteLine("A1) Is s1 normalized to the default form " 
                + "(Form C)?: {0}", System.Convert.ToString(s1.IsNormalized()));
            Console.WriteLine("A2) Is s1 normalized to Form C?:  {0}", 
                System.Convert.ToString(s1.
                IsNormalized(NormalizationForm.FormC)));
            Console.WriteLine("A3) Is s1 normalized to Form D?:  {0}", 
                System.Convert.ToString(s1.
                IsNormalized(NormalizationForm.FormD)));
            Console.WriteLine("A4) Is s1 normalized to Form KC?: {0}", 
                System.Convert.ToString(s1.
                IsNormalized(NormalizationForm.FormKC)));
            Console.WriteLine("A5) Is s1 normalized to Form KD?: {0}", 
                System.Convert.ToString(s1.
                IsNormalized(NormalizationForm.FormKD)));

            Console.WriteLine(divider);

            Console.WriteLine("Set string s2 to each normalized form of " 
                + "string s1.");
            Console.WriteLine();
            Console.WriteLine("U+1E09 = LATIN SMALL LETTER C WITH CEDILLA " 
                + "AND ACUTE");
            Console.WriteLine("U+0033 = DIGIT THREE");
            Console.WriteLine("U+2044 = FRACTION SLASH");
            Console.WriteLine("U+0034 = DIGIT FOUR");
            Console.WriteLine(divider);

            s2 = s1.Normalize();
            Console.Write("B1) Is s2 normalized to the default form " 
                + "(Form C)?: ");
            Console.WriteLine(s2.IsNormalized());
            Show("s2", s2);
            Console.WriteLine();

            s2 = s1.Normalize(NormalizationForm.FormC);
            Console.Write("B2) Is s2 normalized to Form C?: ");
            Console.WriteLine(s2.IsNormalized(NormalizationForm.FormC));
            Show("s2", s2);
            Console.WriteLine();

            s2 = s1.Normalize(NormalizationForm.FormD);
            Console.Write("B3) Is s2 normalized to Form D?: ");
            Console.WriteLine(s2.IsNormalized(NormalizationForm.FormD));
            Show("s2", s2);
            Console.WriteLine();

            s2 = s1.Normalize(NormalizationForm.FormKC);
            Console.Write("B4) Is s2 normalized to Form KC?: ");
            Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKC));
            Show("s2", s2);
            Console.WriteLine();

            s2 = s1.Normalize(NormalizationForm.FormKD);
            Console.Write("B5) Is s2 normalized to Form KD?: ");
            Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKD));
            Show("s2", s2);
            Console.WriteLine();
        }
        catch (System.Exception e) {
            Console.WriteLine(e.get_Message());
        }
    } //main

    private static void Show(String title, String s)
    {
        Console.Write("Characters in string {0} = ", title);
        char myCharArray[] = s.ToCharArray();
        for (int iCtr = 0; iCtr < myCharArray.length; iCtr++) {
            char c = myCharArray[iCtr];
            Console.Write(((System.Int32)c).ToString("X4") + " ");
        }
        Console.WriteLine();
    } //Show
} //Sample
/*
This example produces the following results:

Characters in string s1 = 0063 0301 0327 00BE

U+0063 = LATIN SMALL LETTER C
U+0301 = COMBINING ACUTE ACCENT
U+0327 = COMBINING CEDILLA
U+00BE = VULGAR FRACTION THREE QUARTERS

--------------------------------------------------------------------------------

A1) Is s1 normalized to the default form (Form C)?: False
A2) Is s1 normalized to Form C?:  False
A3) Is s1 normalized to Form D?:  False
A4) Is s1 normalized to Form KC?: False
A5) Is s1 normalized to Form KD?: False

--------------------------------------------------------------------------------

Set string s2 to each normalized form of string s1.

U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
U+0033 = DIGIT THREE
U+2044 = FRACTION SLASH
U+0034 = DIGIT FOUR

--------------------------------------------------------------------------------

B1) Is s2 normalized to the default form (Form C)?: True
Characters in string s2 = 1E09 00BE

B2) Is s2 normalized to Form C?: True
Characters in string s2 = 1E09 00BE

B3) Is s2 normalized to Form D?: True
Characters in string s2 = 0063 0327 0301 00BE

B4) Is s2 normalized to Form KC?: True
Characters in string s2 = 1E09 0033 2044 0034

B5) Is s2 normalized to Form KD?: True
Characters in string s2 = 0063 0327 0301 0033 2044 0034

*/

Vedere anche

Concetti

Normalizzazione e ordinamento