Stream.CanWrite Propiedad

Definición

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

Valor de propiedad

true si el flujo admite escritura; en caso contrario, false.true if the stream supports writing; otherwise, false.

Ejemplos

El siguiente es un ejemplo del uso de la propiedad 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.

Comentarios

Si una clase derivada de Stream no admite la escritura, una llamada a Write, BeginWriteo WriteByte produce una NotSupportedException.If a class derived from Stream does not support writing, a call to Write, BeginWrite, or WriteByte throws a NotSupportedException. En tales casos, Flush se implementa normalmente como un método vacío para garantizar la compatibilidad total con otros tipos de Stream, ya que es válido vaciar una secuencia de solo lectura.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 el flujo está cerrado, esta propiedad devuelve false.If the stream is closed, this property returns false.

Se aplica a

Consulte también: