Comment : écrire des caractères dans une chaîne

Article
08/10/2011

L'exemple de code suivant écrit un certain nombre de caractères à partir d'un tableau de caractères dans une chaîne existante, en commençant à un emplacement spécifié dans le tableau. Utilisez StringWriter à cette fin, comme illustré ci-dessous.

Exemple

Imports System
Imports System.IO
Imports System.Text

Public Class CharsToStr
    Public Shared Sub Main()
        ' Create an instance of StringBuilder that can then be modified.
        Dim sb As New StringBuilder("Some number of characters")
        ' Define and create an instance of a character array from which
        ' characters will be read into the StringBuilder.
        Dim b() As Char = {" ","t","o"," ","w","r","i","t","e"," ","t","o","."}
        ' Create an instance of StringWriter
        ' and attach it to the StringBuilder.
        Dim sw As New StringWriter(sb)
        ' Write three characters from the array into the StringBuilder.
        sw.Write(b, 0, 3)
        ' Display the output.
        Console.WriteLine(sb)
        ' Close the StringWriter.
        sw.Close()
    End Sub
End Class
Imports System.Text

Module Example
   Public Sub Main()
      Dim sb As New StringBuilder()
      Dim flag As Boolean = True
      Dim spellings() As String = { "recieve", "receeve", "receive" }
      sb.AppendFormat("Which of the following spellings is {0}:", flag)
      sb.AppendLine()
      For ctr As Integer = 0 To spellings.GetUpperBound(0)
         sb.AppendFormat("   {0}. {1}", ctr, spellings(ctr))
         sb.AppendLine()
      Next
      sb.AppendLine()
      Console.WriteLine(sb.ToString())
   End Sub
End Module
' The example displays the following output:
'       Which of the following spellings is True:
'          0. recieve
'          1. receeve
'          2. receive

using System;
using System.IO;
using System.Text;

public class CharsToStr
{
    public static void Main()
    {
        // Create an instance of StringBuilder that can then be modified.
        StringBuilder sb = new StringBuilder("Some number of characters");
        // Define and create an instance of a character array from which
        // characters will be read into the StringBuilder.
        char[] b = {' ','t','o',' ','w','r','i','t','e',' ','t','o','.'};
        // Create an instance of StringWriter
        // and attach it to the StringBuilder.
        StringWriter sw = new StringWriter(sb);
        // Write three characters from the array into the StringBuilder.
        sw.Write(b, 0, 3);
        // Display the output.
        Console.WriteLine(sb);
        // Close the StringWriter.
        sw.Close();
    }
}

using System;
using System.Text;

public class Example
{
   public static void Main()
   {
      StringBuilder sb = new StringBuilder();
      bool flag = true;
      string[] spellings = { "recieve", "receeve", "receive" };
      sb.AppendFormat("Which of the following spellings is {0}:", flag);
      sb.AppendLine();
      for (int ctr = 0; ctr <= spellings.GetUpperBound(0); ctr++) {
         sb.AppendFormat("   {0}. {1}", ctr, spellings[ctr]);
         sb.AppendLine();
      }
      sb.AppendLine();
      Console.WriteLine(sb.ToString());
   }
}
// The example displays the following output:
//       Which of the following spellings is True:
//          0. recieve
//          1. receeve
//          2. receive

using namespace System;
using namespace System::IO;
using namespace System::Text;

public ref class CharsToStr
{
public:
    static void Main()
    {
        // Create an instance of StringBuilder that can then be modified.
        StringBuilder^ sb = gcnew StringBuilder("Some number of characters");
        // Define and create an instance of a character array from which
        // characters will be read into the StringBuilder.
        array<Char>^ b = {' ','t','o',' ','w','r','i','t','e',' ','t','o','.'};
        // Create an instance of StringWriter
        // and attach it to the StringBuilder.
        StringWriter^ sw = gcnew StringWriter(sb);
        // Write three characters from the array into the StringBuilder.
        sw->Write(b, 0, 3);
        // Display the output.
        Console::WriteLine(sb);
        // Close the StringWriter.
        sw->Close();
    }
};

int main()
{
    CharsToStr::Main();
}

Programmation fiable

Cet exemple illustre l'utilisation d'une classe StringBuilder pour modifier une chaîne existante. Notez que cette modification nécessite une déclaration using supplémentaire, étant donné que la classe StringBuilder est membre de l'espace de noms System.Text. Aussi, au lieu de définir une chaîne et de la convertir en tableau de caractères, cet exemple crée directement le tableau de caractères et l'initialise.

Ce code génère la sortie suivante :

Some number of characters to

Comment : écrire des caractères dans une chaîne

Exemple

Programmation fiable

Voir aussi

Tâches

Référence

Concepts

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