Introducing .NET Remoting

Abstract

.NET Remoting provides a powerful and high performance way of working with remote objects. Architecturally, .NET Remote objects are a perfect fit for accessing resources across the network without the overhead posed by SOAP based WebServices. .NET Remoting is easier to use than Java’s RMI, but definately more difficult than creating a WebService.

In this article, we will create a remote object that will return an Object read in from the database. I’ve also included an alternate object that omits the database functionality in order to allow those that don’t have a database available to still play with .NET remoting. Make sure you are using Visual Studio.NET Beta 2 when attempting this project.

Step 1: Creating The Shared Library

Click on File->New->Project. Choose to create a new “C# Library” and name it ResumeServerLibrary then click on OK. This will create the “shared vocabulary” that both our .NET Remote client and Server will use to communicate.

The full code is below, if you would like to skip the database access portions, replace the ResumeLoader object with:

public class ResumeLoader : System.MarshalByRefObject
{

public ResumeLoader()
{
System.Console.WriteLine("New Referance Added!");
}

public Resume GetResumeByUserID(decimal userID)
{
return new Resume(1);
}
}

The namespaces required for the object. Please remember, if you’re getting errors that the System.Runtime.Remoting.Channels.Tcp namespace does not exist, make sure you added the referance to System.Runtime.Remoting.dll as described above.

using System;
using System.Runtime;
using System.Data.SqlClient;

Thenamespace we’re using for this particular object is DotNetRemoteTest,the object below is a MarshalByRefObject which means that instead ofpassing ResumeLoader over the wire, we’re creating a referance and allof the work including the database work happenscompletely on the server side.

namespace DotNetRemoteTest
{

public class ResumeLoader : System.MarshalByRefObject
{
private SqlConnection dbConnection;

public ResumeLoader()
{
this.dbConnection = new System.Data.SqlClient.SqlConnection();
this.dbConnection.ConnectionString =
"data source=GRIMSAADO2K;initial catalog=underground;integrated security=SSPI;pers" +
"ist security info=True;workstation id=GRIMSAADO2K;packet size=4096";
/*Your connection string will be different. Database connections are beyond the scope of this article
*If you do not know how to create a database connection, please use the alternate version of this object */
System.Console.WriteLine("New Referance Added!");
}

public Resume GetResumeByUserID(decimal userID)
{
Resume resume = new Resume();
try
{
dbConnection.Open();
SqlCommand cmd = new SqlCommand(
"SELECT ResumeID, UserID, Title, Body FROM Resume as theResume WHERE theResume.UserID="+ userID +""
, dbConnection
);
SqlDataReader aReader = cmd.ExecuteReader();
if(aReader.Read())
{
resume.ResumeID=aReader.GetDecimal(0);
resume.UserID=aReader.GetDecimal(1);
resume.Title=aReader.GetString(2);
resume.Body=aReader.GetString(3);
}
aReader.Close();
dbConnection.Close();
}
catch(Exception x) { resume.Title="Error:"+x; }
return resume;
}
}

The Resume object needs to be serializable in order to be a return type of a remotely referanced .NET Remote object. The reason for this is the object will have to be turned into raw data to be passed over the network, then re-assembled into an object again on the other end.
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