Stream.CanWrite Stream.CanWrite Stream.CanWrite Stream.CanWrite Property

Definition

Ruft beim Überschreiben in einer abgeleiteten Klasse einen Wert ab, der angibt, ob der aktuelle Stream Schreibvorgänge unterstützt.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

Eigenschaftswert

true, wenn der Stream Schreibvorgänge unterstützt, andernfalls false.true if the stream supports writing; otherwise, false.

Beispiele

Folgendes ist ein Beispiel der Verwendung der CanWrite Eigenschaft.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
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.

Hinweise

Wenn eine Klasse von abgeleitet Stream unterstützt nicht das Schreiben, handelt es sich bei eines Aufrufs von Write, BeginWrite, oder WriteByte löst eine NotSupportedException.If a class derived from Stream does not support writing, a call to Write, BeginWrite, or WriteByte throws a NotSupportedException. In solchen Fällen Flush wird in der Regel als eine leere Methode, um sicherzustellen, dass vollständige Kompatibilität mit anderen implementiert Stream Typen, da es sich um einen schreibgeschützten Stream leeren gilt.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.

Wenn der Stream geschlossen ist, gibt diese Eigenschaft false.If the stream is closed, this property returns false.

Gilt für:

Siehe auch