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

CanRead Property
Gets a value indicating whether the OracleLob stream can be read.
Syntax
'Declaration
 
Public Overrides ReadOnly Property CanRead As Boolean
 

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