How to call an AS400 program from C#

alternately, you can use cwbx.dll, an activex automation object from client access
you can call the program directly using cwbx.Programs and not required to create stored procedure

Regarding cwbx, I did a bit of research and it seems I need V5R3 version of Client Access.  Is that true?

definitely not.
you need at least V4R4
http://www-1.ibm.com/support/docview.wss?uid=nas1f2f158ff9d55251a86256751005cec89

I have 2 ideas for you that have worked for me in the past.  I'm normally a VB guy, so I can't give you precise C# code, but I can tell you exactly what you need to do and it's really simple.

First off, if you're using ODBC and using SQL you can simply do a SQL CALL( ).  SQL in the iSeries allows you do a call statement.  The Call statement can call any RPG, CL, Cobol, CLLE, RPGLE, etc. that's on the 400.  You have the option to wait for an answer or to just do the call and exit.  The SQL Call statement can also call a stored procedure.  In fact you could even get really sophisticated and use the call statement to create a source file, then pass in some code and then compile a program and run it.  Basically you could do almost anything.

The syntax is simple.  Just setup your connection like any normal SQL connection and instead of doing a select statement just do somthing like this:  'Call MyCLPgm (PARM1)' or Just 'Call MyRPGPgm' and then execute it.  Simple and elegant.

The other way is to do a REXEC procedure if you're running from windows.  This opens a shell that executes a remote procedure call on the 400.  The only thing here is that you have to have the RPC service running on the 400.  This can be turned on by opening up Operations Navigator and going to the Networking section and then to TCP/IP Servers.  Just start it up and leave it running.  If it's running the the windows REXEC can execute remote procedure calls to the 400.

The shell program requires some SendKeys operations to it because you have log in, etc.  So it's a little more cumbersome that the SQL Call Statement, but here's some VB code that I've used successfully to do the REXEC which will call any program on the 400 also.
---------
Dim strCommand1 As String = "SBMJOB CMD(CALL PGM(LAWMOD7/IFCEXCEDGL) PARM("
        Dim strCommand2 As String 'LawUser and LawJobName
        Dim strCommand3 As String = "))"
        Dim strCommand As String
        Dim ReturnCode
        Dim strPassword As String = ""
        Dim strUser As String = ""
       
        strUser = InputBox("Enter Lawson User ID", "Login to Lawson", "", , )
        strPassword = InputBox("Enter Lawson Password", "Login to Lawson", "", , ) & "~"
        strCommand2 = "'" & strUser & "'" & " '" & InputBox("Enter Lawson GL165 Job Name", "Job to Execute", "", , ) & "'"
        strCommand = strCommand1 & strCommand2 & strCommand3
 
        'Open the command shell with a handle to reactivate using sendkeys
        ReturnCode = Shell(Environ$("WINDIR") & "\system32\rexec.exe iseries -l " & strUser & " " & strCommand, AppWinStyle.NormalFocus)
 
        'Wait a second for the shell command to execute and prompt for the password.
        For x As Integer = 1 To 10000
        Next x
 
        'Activate the shell window
        AppActivate(ReturnCode)
 
        'Send the password to the shell runas program
        SendKeys.SendWait(strPassword)

---------
This is some code that we use to send some data to the AS/400 and to Lawson Financials in particular and then call a Lawson job to process the journal entries we pass in from another system.

The advantage of the SQL Call is that you can wait for results or you can use the submit the job to batch.  You have more control and it's actually a lot simpler.

Let me know if you need more help.  Like I said, my C# skills aren't much beyond reading it and understanding it, but conceptually, I can probably explain what you need to do.

Good luck.

Bryant

Bryav - when you say 'you have the option to wait for an answer or exit', what do you mean?  I would assume that just like a SQL Select, the program waits for the call to finish.

Also, if I do  'Call MyCLPgm (PARM1,PARM2)', where PARM2 is return, how do I access this value?

that's possible if you're using cwbx.program cause parameter can be defined as in/out/InOut
in fact i was recently put lots of interest on usage of cwbx to call as/400 API directly from VB, however, my VB is very poor. If you like to look around, please look at www.dd400.com

after some more researches, i found that performance wise, C/C++ API is better compared to activeX automation object.
please see http://publib.boulder.ibm.com/iseries/v5r2/ic2924/index.htm?info/rzaik/rzaikoverview.htm

I have tried to create a stored procedure but it does not work.  Here is the code:

 private void button1_Click(object sender, EventArgs e)
        {        
           string ConnString = "Provider=IBMDA400.DataSource.1;" +
             "Data Source=172.30.28.36;" +
             "USER ID=DOTNET;" +
             "PASSWORD=DOTNET;" +
             "DEFAULT COLLECTION =MYLIB;";
 
            OleDbConnection myConnection = new OleDbConnection(ConnString);
            OleDbCommand myCommand = new OleDbCommand("CALL MYLIB.ACXTEST(?,?)", myConnection);
            myCommand.CommandType = CommandType.Text;

            //setup the parameters
            OleDbParameter myParameter = new OleDbParameter("INPARM", OleDbType.Char, 5);
            myParameter.Value = this.txtInput.Text;
            myParameter.Direction = ParameterDirection.InputOutput;
            myCommand.Parameters.Add(myParameter);
            OleDbParameter myParameter2 = new OleDbParameter("OUTPARM", OleDbType.Char, 7);
            myParameter2.Value = "String2";
            myParameter2.Direction = ParameterDirection.InputOutput;
            myCommand.Parameters.Add(myParameter2);

            try
            {
                myConnection.Open();
                myCommand.ExecuteNonQuery();
                this.lblReturn.Text = Convert.ToString(myParameter2);
                myConnection.Close();
            }
            catch (Exception excv)
            {
                string ErrorMsg = excv.Message.ToString();
                this.lblReturn.Text = "FAILED " + ErrorMsg;
            }
        }
===========================================

HERE IS AS400 CODE:

CREATE PROCEDURE mylib/ACXTEST(INOUT inparm CHAR ( 5), INOUT    
outparm CHAR ( 7)) DETERMINISTIC NO SQL EXTERNAL NAME          
mylib/ACCTEST PARAMETER STYLE GENERAL                          
CREATE PROCEDURE statement complete.                            

========================================

Here is error message
$exception      {"SQL0440: Routine ACCTEST in MYLIB not found with specified parameters.\r\nCause . . . . . :   A function or procedure with the specified name and compatible arguments was not found. Recovery  . . . :   Specify the correct number and type of parameters on the CALL statement or function invocation. Try the request again."}      System.Exception {System.Data.OleDb.OleDbException}

PROBLEM SOLVED.  It was stored procedures that worked.  I had an discrepancy in my parameter definitions.  Once I fixed that, the pgm worked.