String.GetEnumerator Metodo

Definizione

Recupera un oggetto che può eseguire l'iterazione fra i singoli caratteri di questa stringa.Retrieves an object that can iterate through the individual characters in this string.

public:
 CharEnumerator ^ GetEnumerator();
public CharEnumerator GetEnumerator ();
member this.GetEnumerator : unit -> CharEnumerator
Public Function GetEnumerator () As CharEnumerator

Restituisce

Oggetto enumeratore.An enumerator object.

Esempi

Nell'esempio seguente vengono scorsi i caratteri in più stringhe e vengono visualizzate le informazioni relative ai singoli caratteri.The following example iterates the characters in several strings and displays information about their individual characters. Usa il costrutto di iterazione del linguaggio anziché una chiamata al metodo GetEnumerator.It uses the language iteration construct rather than a call to the GetEnumerator method.

using namespace System;

void EnumerateAndDisplay(String^ phrase)
{
   Console::WriteLine("The characters in the string \"{0}\" are:", 
                      phrase);

   int CharCount = 0;
   int controlChars = 0;
   int alphanumeric = 0;
   int punctuation = 0;

   for each (Char ch in phrase) {
      Console::Write("'{0}' ", (! Char::IsControl(ch)) ? ch.ToString() : 
                                "0x" + Convert::ToUInt16(ch).ToString("X4"));
      if (Char::IsLetterOrDigit(ch)) 
         alphanumeric++;
      else if (Char::IsControl(ch)) 
         controlChars++;
      else if (Char::IsPunctuation(ch)) 
         punctuation++;             
      CharCount++;
   }

   Console::WriteLine("\n   Total characters:        {0,3}", CharCount);
   Console::WriteLine("   Alphanumeric characters: {0,3}", alphanumeric);
   Console::WriteLine("   Punctuation characters:  {0,3}", punctuation);
   Console::WriteLine("   Control Characters:      {0,3}\n", controlChars);
}

int main()
{
   EnumerateAndDisplay("Test Case");
   EnumerateAndDisplay("This is a sentence.");
   EnumerateAndDisplay("Has\ttwo\ttabs");
   EnumerateAndDisplay("Two\nnew\nlines");
}
// The example displays the following output:
//    The characters in the string "Test Case" are:
//    'T' 'e' 's' 't' ' ' 'C' 'a' 's' 'e'
//       Total characters:          9
//       Alphanumeric characters:   8
//       Punctuation characters:    0
//       Control Characters:        0
//    
//    The characters in the string "This is a sentence." are:
//    'T' 'h' 'i' 's' ' ' 'i' 's' ' ' 'a' ' ' 's' 'e' 'n' 't' 'e' 'n' 'c' 'e' '.'
//       Total characters:         19
//       Alphanumeric characters:  15
//       Punctuation characters:    1
//       Control Characters:        0
//    
//    The characters in the string "Has       two     tabs" are:
//    'H' 'a' 's' '0x0009' 't' 'w' 'o' '0x0009' 't' 'a' 'b' 's'
//       Total characters:         12
//       Alphanumeric characters:  10
//       Punctuation characters:    0
//       Control Characters:        2
//    
//    The characters in the string "Two
//    new
//    lines" are:
//    'T' 'w' 'o' '0x000A' 'n' 'e' 'w' '0x000A' 'l' 'i' 'n' 'e' 's'
//       Total characters:         13
//       Alphanumeric characters:  11
//       Punctuation characters:    0
//       Control Characters:        2
using System;

class Example
{
   public static void Main() 
   {
      EnumerateAndDisplay("Test Case");
      EnumerateAndDisplay("This is a sentence.");
      EnumerateAndDisplay("Has\ttwo\ttabs" );
      EnumerateAndDisplay("Two\nnew\nlines");
   }

   static void EnumerateAndDisplay(String phrase)
   {
      Console.WriteLine("The characters in the string \"{0}\" are:",
                        phrase);

      int CharCount = 0;
      int controlChars = 0;
      int alphanumeric = 0;
      int punctuation = 0;

      foreach (var ch in phrase) {
         Console.Write("'{0}' ", ! Char.IsControl(ch) ? ch.ToString() : 
                                     "0x" + Convert.ToUInt16(ch).ToString("X4"));
         if (Char.IsLetterOrDigit(ch)) 
            alphanumeric++;
         else if (Char.IsControl(ch)) 
            controlChars++;
         else if (Char.IsPunctuation(ch)) 
            punctuation++;             
         CharCount++;
      }

      Console.WriteLine("\n   Total characters:        {0,3}", CharCount);
      Console.WriteLine("   Alphanumeric characters: {0,3}", alphanumeric);
      Console.WriteLine("   Punctuation characters:  {0,3}", punctuation);
      Console.WriteLine("   Control Characters:      {0,3}\n", controlChars);
   }
}
// The example displays the following output:
//    The characters in the string "Test Case" are:
//    'T' 'e' 's' 't' ' ' 'C' 'a' 's' 'e'
//       Total characters:          9
//       Alphanumeric characters:   8
//       Punctuation characters:    0
//       Control Characters:        0
//    
//    The characters in the string "This is a sentence." are:
//    'T' 'h' 'i' 's' ' ' 'i' 's' ' ' 'a' ' ' 's' 'e' 'n' 't' 'e' 'n' 'c' 'e' '.'
//       Total characters:         19
//       Alphanumeric characters:  15
//       Punctuation characters:    1
//       Control Characters:        0
//    
//    The characters in the string "Has       two     tabs" are:
//    'H' 'a' 's' '0x0009' 't' 'w' 'o' '0x0009' 't' 'a' 'b' 's'
//       Total characters:         12
//       Alphanumeric characters:  10
//       Punctuation characters:    0
//       Control Characters:        2
//    
//    The characters in the string "Two
//    new
//    lines" are:
//    'T' 'w' 'o' '0x000A' 'n' 'e' 'w' '0x000A' 'l' 'i' 'n' 'e' 's'
//       Total characters:         13
//       Alphanumeric characters:  11
//       Punctuation characters:    0
//       Control Characters:        2
Module Example
   Sub Main()
      EnumerateAndDisplay("Test Case")
      EnumerateAndDisplay("This is a sentence.")
      EnumerateAndDisplay("Has" & vbTab & "two" & vbTab & "tabs")
      EnumerateAndDisplay("Two" & vbLf & "new" & vbLf & "lines")
   End Sub 
       
   Sub EnumerateAndDisplay(phrase As String)
      Console.WriteLine("The characters in the string ""{0}"" are:", phrase)
       
      Dim charCount As Integer = 0
      Dim controlChars As Integer = 0
      Dim alphanumeric As Integer = 0
      Dim punctuation As Integer = 0
        
      For Each ch In phrase          
         Console.Write("'{0}' ", If(Not Char.IsControl(ch), ch, 
                                     "0x" + Convert.ToUInt16(ch).ToString("X4")))
         If Char.IsLetterOrDigit(ch) Then 
            alphanumeric += 1
         Else If Char.IsControl(ch) Then 
            controlChars += 1
         Else If Char.IsPunctuation(ch) Then 
            punctuation += 1             
         End If
         CharCount += 1
      Next

      Console.WriteLine()
      Console.WriteLine("   Total characters:        {0,3}", CharCount)
      Console.WriteLine("   Alphanumeric characters: {0,3}", alphanumeric)
      Console.WriteLine("   Punctuation characters:  {0,3}", punctuation)
      Console.WriteLine("   Control Characters:      {0,3}", controlChars)
      Console.WriteLine()
    End Sub 
End Module 
' This example displays the following output:
'    The characters in the string "Test Case" are:
'    'T' 'e' 's' 't' ' ' 'C' 'a' 's' 'e'
'       Total characters:          9
'       Alphanumeric characters:   8
'       Punctuation characters:    0
'       Control Characters:        0
'    
'    The characters in the string "This is a sentence." are:
'       'T' 'h' 'i' 's' ' ' 'i' 's' ' ' 'a' ' ' 's' 'e' 'n' 't' 'e' 'n' 'c' 'e' '.'
'          Total characters:         19
'          Alphanumeric characters:  15
'          Punctuation characters:    1
'          Control Characters:        0
'       
'       The characters in the string "Has       two     tabs" are:
'       'H' 'a' 's' '0x0009' 't' 'w' 'o' '0x0009' 't' 'a' 'b' 's'
'          Total characters:         12
'          Alphanumeric characters:  10
'          Punctuation characters:    0
'          Control Characters:        2
'       
'       The characters in the string "Two
'       new
'       lines" are:
'       'T' 'w' 'o' '0x000A' 'n' 'e' 'w' '0x000A' 'l' 'i' 'n' 'e' 's'
'          Total characters:         13
'          Alphanumeric characters:  11
'          Punctuation characters:    0
'          Control Characters:        2

Commenti

Suggerimento

Anziché chiamare il metodo GetEnumerator per recuperare un oggetto CharEnumerator da usare per enumerare una stringa, è necessario usare invece il costrutto di iterazione del linguaggio ( C#in, C++in/CLR e in Visual Basic).Rather than calling the GetEnumerator method to retrieve a CharEnumerator object that you then use to enumerate a string, you should instead use your language's iteration construct (in C#, in C++/CLR, and in Visual Basic). foreach in C#, per ogni in C++/CLR e per each in Visual Basic).foreach in C#, for each in C++/CLR, and For Each in Visual Basic).

Questo metodo consente di scorrere i singoli caratteri in una stringa.This method enables you to iterate the individual characters in a string. Ad esempio, le istruzioni Visual Basic For Each C# e foreach richiamano questo metodo per restituire un oggetto CharEnumerator che può fornire accesso in sola lettura ai caratteri in questa istanza di stringa.For example, the Visual Basic For Each and C# foreach statements invoke this method to return a CharEnumerator object that can provide read-only access to the characters in this string instance.

Si applica a

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