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Stream.CanWrite Propiedad

  • Referencia

Definición

Espacio de nombres:
System.IO
Ensamblado:
System.IO.dll
Ensamblado:
System.Runtime.dll
Ensamblado:
mscorlib.dll
Ensamblado:
netstandard.dll
Source:
Stream.cs
Source:
Stream.cs
Source:
Stream.cs

Cuando se reemplaza en una clase derivada, obtiene un valor que indica si la secuencia actual admite escritura.

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

Valor de propiedad

Boolean

true si el flujo admite escritura; en caso contrario, false.

Ejemplos

A continuación se muestra un ejemplo de uso de la CanWrite propiedad .

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.

Comentarios

Si una clase derivada de Stream no admite la escritura, una llamada a Write, BeginWriteo WriteByte inicia una NotSupportedExceptionexcepción . En tales casos, Flush normalmente se implementa como un método vacío para garantizar la compatibilidad completa con otros Stream tipos, ya que es válido vaciar una secuencia de solo lectura.

Se aplica a

Consulte también