Overrides Stream
This instance method reads a specified amount of bytes from the OracleBFile
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 offset of the byte array buffer to be populated.
count
The amount of bytes to read.
Return Value
The return value indicates the number of bytes read from the BFILE
, that is, the external 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
- Either the offset
or the count
parameter is less than 0
or the offset
is greater than or equal to the buffer
.Length
or the offset
and the count
together are greater than buffer
.Length
.
Remarks
The LOB data is read starting from the position specified by the Position
property.
Example
// Database Setup, if you have not done so yet. /* Log on as DBA (SYS or SYSTEM) that has CREATE ANY DIRECTORY privilege. CREATE OR REPLACE DIRECTORY MYDIR AS 'C:\TEMP'; */ // C# using System; using Oracle.DataAccess.Client; using Oracle.DataAccess.Types; class ReadSample { static void Main() { // Create MYDIR directory object as indicated previously and create a file // MyFile.txt with the text ABCDABC under C:\TEMP directory. // Note that the byte representation of the ABCDABC is 65666768656667 string constr = "User Id=scott;Password=tiger;Data Source=oracle"; OracleConnection con = new OracleConnection(constr); con.Open(); OracleBFile bFile = new OracleBFile(con, "MYDIR", "MyFile.txt"); // Open the OracleBFile bFile.OpenFile(); // Read 7 bytes into readBuffer, starting at buffer offset 0 byte[] readBuffer = new byte[7]; int bytesRead = bFile.Read(readBuffer, 0, 7); // Prints "bytesRead = 7" Console.WriteLine("bytesRead = " + bytesRead); // Prints "readBuffer = 65666768656667" Console.Write("readBuffer = "); for(int index = 0; index < readBuffer.Length; index++) { Console.Write(readBuffer[index]); } Console.WriteLine(); // Close the OracleBFile bFile.CloseFile(); bFile.Close(); bFile.Dispose(); con.Close(); con.Dispose(); } }