Read

Overrides Stream

This instance method reads a specified amount of bytes from the ODP.NET LOB instance and populates the buffer.

Declaration

// C#
public override int Read(byte[] buffer, int offset, int count);

Parameters

buffer

The byte array buffer to be populated.
offset

The starting offset (in bytes) at which the buffer is populated.
count

The amount of bytes to read.

Return Value

The return value indicates the number of bytes read from the LOB.

Exceptions

ObjectDisposedException - The object is already disposed.

InvalidOperationException - The OracleConnection is not open or has been closed during the lifetime of the object.

ArgumentOutOfRangeException - This exception is thrown if any of the following conditions exist:

The offset or the count parameter is less than 0.
The offset is greater than or equal to the buffer.Length.
The offset and the count together are greater than the buffer.Length.

Remarks

The LOB data is read starting from the position specified by the Position property.

Example

// C#
 
using System;
using Oracle.DataAccess.Client;
using Oracle.DataAccess.Types;
 
class ReadSample
{
  static void Main()
  {
    string constr = "User Id=scott;Password=tiger;Data Source=oracle";
    OracleConnection con = new OracleConnection(constr);
    con.Open();
 
    OracleBlob blob = new OracleBlob(con);
      
    // Write 3 bytes, starting at buffer offset 1
    byte[] writeBuffer = new byte[4] {1, 2, 3, 4};
    blob.Write(writeBuffer, 1, 3);
 
    // Reset the Position for Read
    blob.Position = 1;
 
    // Read 2 bytes into buffer starting at buffer offset 1
    byte[] readBuffer = new byte[4];    
    int bytesRead = blob.Read(readBuffer, 1, 2);
 
    // Prints "bytesRead  = 2"
    Console.WriteLine("bytesRead  = " + bytesRead);    
 
    // Prints "readBuffer = 0340"
    Console.Write("readBuffer = ");
    for(int index = 0; index <  readBuffer.Length; index++)
    {
      Console.Write(readBuffer[index]);
    }
    Console.WriteLine();
 
    blob.Close();
    blob.Dispose();
 
    con.Close();
    con.Dispose();
  }
}