Stream.CanRead Eigenschaft

Definition

Ruft beim Überschreiben in einer abgeleiteten Klasse einen Wert ab, der angibt, ob der aktuelle Stream Lesevorgänge unterstützt.When overridden in a derived class, gets a value indicating whether the current stream supports reading.

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

Eigenschaftswert

Boolean

true, wenn der Stream Lesevorgänge unterstützt, andernfalls false.true if the stream supports reading; otherwise, false.

Beispiele

Im folgenden finden Sie ein Beispiel für die Verwendung der- CanRead Eigenschaft.The following is an example of using the CanRead property.

using namespace System;
using namespace System::IO;
int main( void )
{
   FileStream^ fs = gcnew FileStream( "MyFile.txt",FileMode::OpenOrCreate,FileAccess::Read );
   if ( fs->CanRead && fs->CanWrite )
   {
      Console::WriteLine( "MyFile.txt can be both written to and read from." );
   }
   else
   {
      Console::WriteLine( "MyFile.txt is not writable" );
   }

   return 0;
}

using System;
using System.IO;

class TestRW
{
    public static void Main(String[] args)
    {
        FileStream fs = new FileStream("MyFile.txt", FileMode.OpenOrCreate, FileAccess.Read);
        if (fs.CanRead && fs.CanWrite)
        {
            Console.WriteLine("MyFile.txt can be both written to and read from.");
        }
        else if (fs.CanRead)
        {
            Console.WriteLine("MyFile.txt is not writable.");
        }
    }
}
Imports System.IO

Class TestRW

    Public Shared Sub Main()
        Dim fs As New FileStream("MyFile.txt", FileMode.OpenOrCreate, FileAccess.Read)
        If fs.CanRead And fs.CanWrite Then
            Console.WriteLine("MyFile.txt can be both written to and read from.")
        Else
            If fs.CanRead Then
                Console.WriteLine("MyFile.txt is not writable.")
            End If
        End If
    End Sub
End Class

Hinweise

Wenn eine von abgeleitete Klasse Stream Lesevorgänge nicht unterstützt, lösen Aufrufe der Read ReadByte Methoden, und eine aus BeginRead NotSupportedException .If a class derived from Stream does not support reading, calls to the Read, ReadByte, and BeginRead methods throw a NotSupportedException.

Gilt für:

Weitere Informationen