Hi all refer to these post : here1 and here2 at last I solve my problem by build a asynchronous solution,and it work well!!! but there is a problem that i face with it,now my code is like this:

class MyProcessStarter
    {
        private Process process;
        private StreamWriter myStreamWriter;
        private static StringBuilder shellOutput = null;
        public String GetShellOutput { get { return shellOutput.ToString(); }}

        public MyProcessStarter(){
            shellOutput = new StringBuilder("");
            process = new Process();            
            process.StartInfo.FileName = "sqlplus";
            process.StartInfo.UseShellExecute = false;
            process.StartInfo.CreateNoWindow = true;
            process.OutputDataReceived += new DataReceivedEventHandler(ShellOutputHandler);

            process.StartInfo.RedirectStandardInput = true;
            process.StartInfo.RedirectStandardOutput = true;
            //process.StartInfo.RedirectStandardError = true;
            process.Start();
            myStreamWriter = process.StandardInput;
            process.BeginOutputReadLine();
        }

        private static void ShellOutputHandler(object sendingProcess,DataReceivedEventArgs outLine)
        {
            if (!String.IsNullOrEmpty(outLine.Data))
                shellOutput.Append(Environment.NewLine + outLine.Data);
        }

        public void closeConnection()
        {
            myStreamWriter.Close();
            process.WaitForExit();
            process.Close(); 
        }

        public void RunCommand(string arguments)
        {
            myStreamWriter.WriteLine(arguments);
            myStreamWriter.Flush();
            process.WaitForExit(100);
            Console.WriteLine(shellOutput);
            Console.WriteLine("============="+Environment.NewLine);
            process.WaitForExit(2000);
            Console.WriteLine(shellOutput);            
        }
    } 

and my input is like this:

 myProcesStarter.RunCommand("myusername/mypassword");
 Console.writeline(myProcesStarter.GetShellOutput);

but take a look at my out put:

SQL*Plus: Release 11.1.0.6.0 - Production on Thu May 20 11:57:38 2010
Copyright (c) 1982, 2007, Oracle.  All rights reserved.
=============


SQL*Plus: Release 11.1.0.6.0 - Production on Thu May 20 11:57:38 2010
Copyright (c) 1982, 2007, Oracle.  All rights reserved.
Enter user-name: 
Connected to:
Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

as u see the output for run a function is not same in different time!So now would you do me a faver and help me that how I can wait until all the output done in other mean how I can customize my process to wait until output finishing ?? because I want to write a sqlcompiler so I need the exact output of shell.

plz help me soon.thanxxxxxxxxxxxx :X