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Devart.Data.Oracle Namespace / OracleLob Class / CanRead Property
Example

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    CanRead Property
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    Gets a value indicating whether the OracleLob stream can be read.
    Syntax
    'Declaration
     
    Public Overrides ReadOnly Property CanRead As Boolean
    public override bool CanRead {get;}

    Property Value

    true if the OracleLob stream supports reading; false if a OracleLob is closed, disposed, or Null.
    Remarks
    Use CanRead property to determine whether OracleLob object supports reading. OracleLob can not be read from if it has Null value.
    Example
    static void ReverseBlob() 
    { 
            byte[] byteArray = { (byte)'A', (byte)'B', (byte)'C' }; 
            OracleLob blobFrom = new OracleLob(OracleDbType.Blob);
            blobFrom.Write(byteArray, 0, byteArray.Length);
            //blobFrom.ToString() = "ABC" 
    
            OracleLob blobTo = new OracleLob(OracleDbType.Blob); 
            ........
            //reverse OracleLob 
            if (blobFrom.CanSeek && blobFrom.CanRead && blobTo.CanWrite) 
                    for (blobFrom.Seek(-1, System.IO.SeekOrigin.End); ;blobFrom.Position -= 2) 
                    { 
                            blobTo.WriteByte((byte)blobFrom.ReadByte()); 
                            if (blobFrom.Position == 1) break; 
                    } 
            //blobTo.ToString() = "CBA"; 
    }
    Private Sub ReverseBlob()
            Dim byteArray As Byte() = New Byte() {AscW("A"c), AscW("B"c), AscW("C"c)}
            Dim blobFrom As New OracleLob(OracleDbType.Blob)
            blobFrom.Write(byteArray, 0, byteArray.Length)
            ' blobFrom.ToString() = "ABC"
    
            Dim blobTo As New OracleLob(OracleDbType.Blob)
            ........
            ' reverse OracleLob
            If ((blobFrom.CanSeek AndAlso blobFrom.CanRead) AndAlso blobTo.CanWrite) Then
                    blobFrom.Seek(CLng(-1), System.IO.SeekOrigin.End)
                    Do While True
                            blobTo.WriteByte(CByte(blobFrom.ReadByte))
                            If (blobFrom.Position = 1) Then
                                    Return
                            End If
                            blobFrom.Position = blobFrom.Position - 2
                    Loop
            End If
            ' blobTo.ToString() = "CBA";
    End Sub
    Requirements

    Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

    See Also