CanRead Property

In This Topic

Gets a value indicating whether the OracleLob stream can be read.

Syntax

Visual Basic
C#

'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

csharp

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"; 
}

Visual Basic

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

Reference

OracleLob Class
OracleLob Members

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