FileStream.CanRead FileStream.CanRead FileStream.CanRead FileStream.CanRead Property

定義

現在のストリームが読み込みをサポートしているかどうかを示す値を取得します。Gets a value that indicates whether the current stream supports reading.

public:
 virtual property bool CanRead { bool get(); };
public override bool CanRead { get; }
member this.CanRead : bool
Public Overrides ReadOnly Property CanRead As Boolean

プロパティ値

ストリームが読み取りをサポートしている場合は true。ストリームが閉じているか、書き込み専用アクセスで開かれた場合は falsetrue if the stream supports reading; false if the stream is closed or was opened with write-only access.

次の例を使用して、CanReadプロパティ。The following example demonstrates a use of the CanRead property. このコードの出力は「MyFile.txt 書き込みができません」The output of this code is "MyFile.txt is not writable." 出力メッセージ「MyFile.txt に書き込まれるおよびできる読み取ったりします。」、変更を取得する、FileAccessパラメーターをReadWriteで、FileStreamコンス トラクター。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 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
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

注釈

派生したクラスの場合Stream読み取りをサポートしませんへの呼び出し、 ReadReadByte、およびBeginReadメソッドでスロー、NotSupportedExceptionします。If a class derived from Stream does not support reading, calls to the Read, ReadByte, and BeginRead methods throw a NotSupportedException.

このプロパティを返しますのかどうかは、ストリームが閉じている、falseします。If the stream is closed, this property returns false.

適用対象

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