Stream.CanWrite Propriété

Définition

En cas de remplacement dans une classe dérivée, obtient une valeur indiquant si le flux actuel prend en charge l'écriture.When overridden in a derived class, gets a value indicating whether the current stream supports writing.

public:
 abstract property bool CanWrite { bool get(); };
public abstract bool CanWrite { get; }
member this.CanWrite : bool
Public MustOverride ReadOnly Property CanWrite As Boolean

Valeur de propriété

true si le flux prend en charge l'écriture ; sinon, false.true if the stream supports writing; otherwise, false.

Exemples

Voici un exemple d’utilisation de la propriété CanWrite.The following is an example of using the CanWrite property.

using namespace System;
using namespace System::IO;
int main()
{
   FileStream^ fs = gcnew FileStream( "MyFile.txt",FileMode::OpenOrCreate,FileAccess::Write );
   if ( fs->CanRead && fs->CanWrite )
   {
      Console::WriteLine( "MyFile.txt can be both written to and read from." );
   }
   else
   if ( fs->CanWrite )
   {
      Console::WriteLine( "MyFile.txt is writable." );
   }
}

//This code outputs "MyFile.txt is writable."
//To get the output message "MyFile.txt can be both written to and read from.",
//change the FileAccess parameter to ReadWrite in the FileStream constructor.
using System;
using System.IO;

class TestRW
{
  public static void Main(String[] args)
  {
    FileStream fs = new FileStream("MyFile.txt", FileMode.OpenOrCreate,
       FileAccess.Write);
    if (fs.CanRead && fs.CanWrite) {
        Console.WriteLine("MyFile.txt can be both written to and read from.");
    }
    else if (fs.CanWrite) {
        Console.WriteLine("MyFile.txt is writable.");
    }
  }
}
//This code outputs "MyFile.txt is writable."
//To get the output message "MyFile.txt can be both written to and read from.",
//change the FileAccess parameter to ReadWrite in the FileStream constructor.
Imports System.IO

Class TestRW    

    Public Shared Sub Main()
        Dim fs As New FileStream("MyFile.txt", FileMode.OpenOrCreate, _
           FileAccess.Write)
        If fs.CanRead And fs.CanWrite Then
            Console.WriteLine("MyFile.txt can be both written to and read from.")
        Else
            If fs.CanWrite Then
                Console.WriteLine("MyFile.txt is writable.")
            End If
        End If
    End Sub
End Class

'This code outputs "MyFile.txt is writable."
'To get the output message "MyFile.txt can be both written to and read from.",
'change the FileAccess parameter to ReadWrite in the FileStream constructor.

Remarques

Si une classe dérivée de Stream ne prend pas en charge l’écriture, un appel à Write, BeginWriteou WriteByte lève une NotSupportedException.If a class derived from Stream does not support writing, a call to Write, BeginWrite, or WriteByte throws a NotSupportedException. Dans ce cas, Flush est généralement implémenté comme une méthode vide pour garantir une compatibilité complète avec d’autres types de Stream, car il est valide pour vider un flux en lecture seule.In such cases, Flush is typically implemented as an empty method to ensure full compatibility with other Stream types since it's valid to flush a read-only stream.

Si le flux est fermé, cette propriété retourne false.If the stream is closed, this property returns false.

S’applique à

Voir aussi