Migration to 64-bit: ODBC

Most people migrating their application want to move ahead and take advantage of new technologies and new operating systems.

So if you had a VB6 application and you migrated it with us to .NET we will recommend and automate the process to use ADO.NET.

Why?

You can still use ODBC but i will list some compelling reasons:

* There a very fast ADO.NET drivers available. Using ODBC implies addind an interop overhead that can affect performance.
* Some vendors do not support and/or certify the use of ODBC drivers for .NET. So in those cases if you use ODBC your are on your own.
During my consulting experience I have seen several problems using ODBC drivers ranging from just poor performance, problems with some SQL statements, stored procedures calls, database specific features or complete system inestability.
* and also problems running in 64-bit.

This last one is very concerning. If you made all the effort to migrate an application to .NET and run it on for example on a Windows 2003 64 bit server it wont be able to use your 32-bit ODBC drivers unless you go to the the Build tab, and set Platform Target to "x86".

This is very sad because your application cannot take advantage of all the 64 bit resources.

If you are lucky enough you might find a 64 bit version of your ODBC driver but I will really recommend going straigth to 64-bit and use ADO.NET. And that's exactly what we can really help you to do specially in our version 2.2 of the VBUC.

Migration of ActiveX UserDocuments to C# or .NET

This post describes an an interesting workaround that you can use to support the migration of ActiveX Documents with the Artinsoft Visual Basic Upgrade Companion which is one of the Artinsoft \ Mobilize.NET tools you can use to modernize your Visual Basic, Windows Forms and PowerBuilder applications.

Currently the Visual Basic Upgrade Companion does not allow you to process ActiveX Document directly, but there is a workaround: in general ActiveX Document are something really close to an User Control which is a element that is migrated automatically by the Visual Basic Upgrade Companion.

This post provides a link to a tool (DOWNLOAD TOOL) that can fix your VB6 projects, so the Visual Basic Upgrade Companion processes them. To run the tool:

1) Open the command prompt

2) Go to the Folder where the .vbp file is located

3) Execute a command line command like:

 FixUserDocuments Project1.vbp

This will generate a new project called Project1_modified.vbp. Migrate this new project and now UserDocuments will be supported.

VB6 allows you to create UserDocuments, which can be embedded inside an ActiveX container. The most common one is Internet Explorer. After compilation, the document is contained in a Visual Basic Document file (.VBD) and the server is contained in either an .EXE or .DLL file. During development, the project is in a .DOB file, which is a plain text file containing the definitions of the project’s controls, source code, and so on.

If an ActiveX document project contains graphical elements that cannot be stored in text format, they will be kept in a .DOX file. The .DOB and .DOX files in an ActiveX document project are parallel to the .FRM and .FRX files of a regular Visual Basic executable project. 

The trick to support ActiveX documents is that in general they are very similar to UserControls, and .NET UserControls can also be hosted in a WebBrowser. The following command line tool can be used to update your VB6 projects. It will generate a new solution where UserDocuments will be defined as UserControls.

If you have an ActiveX document like the following: 

Then after running the tool you will have an Project like the following:

So after you have upgraded the projet with the Fixing tool, open the Visual Basic Upgrade Companion  and migrate your project.

After migration you will get something like this:

To use your migrated code embedded in a Web Browser copy the generated assemblies and .pdb to the directory you will publish:

Next create an .HTM page. For example UserDocument1.htm

The contents of that page should be something like the following:

 Now all that is left is to publish the output directory.
To publish your WinForms user control follow these steps.

2. A Wizard to create a Virtual Directory will appear.

 Click Next

 Name the directory as you want. For example Project1. Click Next

 Select the location of your files. Click the Browse button to open a dialog box where you can select your files location. Click Next

 Check the read and run scripts checks and click next

 Now Click Finish

3. Properties for the Virtual Directory will look like this:

NOTE: to see this dialog right click over the virtual directory

4. Now just browse to the address lets say http:\\localhost\Project1\UserDocument1.htm

 And that should be all! :)

The colors are different because of the Host configuration however a simple CSS like:

<style>

 body {background-color: gray;}

</style>

Can make the desired change:

Notice that there will be security limitations, for example for thinks like MessageBoxes.

You can allow restricted operations by setting your site as a restricted site:

For example:

Restrictions

The constraints for this solution include:

* This solutions requires Windows operating system on the client side

* Internet Explorer 6.0 is the only browser that provides support for this type of hosting

* It requires .NET runtime to be installed on the client machine.

* It also requires Windows 2000 and IIS 5.0 or above on the server side

Due to all of the above constraints, it might be beneficial to detect the capabilities of the client machine and then deliver content that is appropriate to them. For example, since forms controls hosted in IE require the presence of the .NET runtime on the client machine, we can write code to check if the client machine has the .NET runtime installed. You can do this by checking the value of the Request.Browser.ClrVersion property. If the client machine has .NET installed, this property will return the version number; otherwise it will return 0.0.

Adding a script like:

<script>

 if ((navigator.userAgent.indexOf(".NET CLR")>-1))

 {

      //alert ("CLR available " +navigator.userAgent);

 }

  else

      alert(".NET SDK/Runtime is not available for us from within " +            "your web browser or your web browser is not supported." +            " Please check with http://msdn.microsoft.com/net/ for " +            "appropriate .NET runtime for your machine.");

</script>

Will help with that.

 References:

ActiveX Documents Definitions:

http://www.aivosto.com/visdev/vdmbvis58.html

Hosting .NET Controls in IE

http://www.15seconds.com/issue/030610.htm

Pesky VB Migration details

During migratio of a simple project, we found an interesting migration details.

The solution has a project with two Forms. Form1 and Form2. Form1 has a command button and in the Click for that command button it performs a code like UnLoad Form2.

But it could happen that Form2 has not been loaded but in VB6 it is not a problem. In .NET the code will be something like form2.Close() and it could cause problems.

A possible fix is to add some flag that indicates if the form was instanciated and the call the event.

PGP in Java

Recenlty following a post in an AS400 Java Group, someone asked about a method for signing and verifying a file with PGP.
I though, "Damn, that seems like a very common thing, it shouldn't be that difficult", and started google'ing for it.
I found as the poster said that the Bouncy Castle API can be used but it was not easy.

Well so I learned a lot about PGP and the Bouncy Castle and thanks god, Tamas Perlaky posted a great sample that signs a file, so I didn't have to spend a lot of time trying to figure it out.

I'm copying Tamas Post because, I had problems accesing the site so here is the post just as Tamas published it:

"To build this you will need to obtain the following depenencies.  The Bouncy Castle versions may need to be different based on your JDK level.

  bcpg-jdk15-141.jar
  bcprov-jdk15-141.jar
  commons-cli-1.1.jar

Then you can try something like:
  java net.tamas.bcpg.DecryptAndVerifyFile -d test2_secret.asc -p secret -v test1_pub.asc -i test.txt.asc -o verify.txt
And expect to get a verify.txt that's the same as test.txt.  Maybe.
Here’s the download: PgpDecryptAndVerify.zip"

And this is the original link: http://www.tamas.net/Home/PGP_Samples.html

Thanks a lot Tamas

VSS reset admin password

I had to access an old VSS database and nobody remember any password or the admin password.

The tool from this page http://not42.com/2005/06/16/visual-source-safe-admin-password-reset 

This was a lifesaver!

Coldfusion and Memory Problems

If you have heavy processes in Coldfusion a nice thing is to track them with the JVMSTAT tool.

You can get the JVMStat tool from http://java.sun.com/performance/jvmstat/

 And this post shows some useful information of how to use the tool with Coldfusion

http://www.petefreitag.com/item/141.cfm

Scripting your applications in .NET Part 2

Just more details about scripting

Using the MS Scripting Object

The MS Scripting Object can be used in .NET applications. But it has several limitations.

The main limitation it has is that all scripted objects must be exposed thru pure COM. The scripting object is a COM component that know nothing about .NET

In general you could do something like the following to expose a component thru COM:

   [System.Runtime.InteropServices.ComVisible(true)]

    public partial class frmTestVBScript  : Form
    {
        //Rest of code
    }
 

NOTE: you can use that code to do a simple exposure of the form to COM Interop. However to provide a full exposure of a graphical component like a form or user control you should use the Interop Form ToolKit from Microsoft http://msdn.microsoft.com/en-us/vbasic/bb419144.aspx

To expose an object in COM. But most of the properties and methods in a System.Windows.Forms.Form class, use native types instead of COM types.

As you could see in the Backcolor property example:

public int MyBackColor

{

            get { return System.Drawing.ColorTranslator.ToOle(this.BackColor); }

            set { this.BackColor = System.Drawing.ColorTranslator.FromOle(value); }

}

• The problem with properties such as those is that System.Drawing.Color is not COM exposable.
• Your script will expect an object exposing COM-compatible properties.
• Another problem with that is that there might be some name collision.

Using Forms

In general to use your scripts without a lot of modification to your scripts you should do something like this:

• Your forms must mimic the interfaces exposed by VB6 forms. To do that you can use a tool like OLE2View and take a look at the interfaces in VB6.OLB
• Using those interfaces create an interface in C#
• Make your forms implement that interface.
• If your customers have forms that they expose thru com then if those forms add new functionality do this:
• Create a new interface, that extends the basic one you have and

I’m attaching an application showing how to to this.

Performing a CreateObject and Connecting to the Database

The CreateObject command can still be used. To allow compatibility the .NET components must expose the same ProgIds that the used.

ADODB can still be used, and probably RDO and ADO (these last two I haven’t tried a lot)

So I tried a simple script like the following to illustrate this:

Sub ConnectToDB
'declare the variable that will hold new connection object

Dim Connection 
'create an ADO connection object

Set Connection=CreateObject("ADODB.Connection")
'declare the variable that will hold the connection string

Dim ConnectionString 
'define connection string, specify database driver and location of the database 

ConnectionString = "Driver={SQL Server};Server=MROJAS\SQLEXPRESS;Database=database1;TrustedConnection=YES"

'open the connection to the database
Connection.Open ConnectionString 
MsgBox "Success Connect. Now lets try to get data"
'declare the variable that will hold our new object

Dim Recordset   
'create an ADO recordset object
Set Recordset=CreateObject("ADODB.Recordset") 
'declare the variable that will hold the SQL statement

Dim SQL    
SQL="SELECT * FROM Employees" 
'Open the recordset object executing the SQL statement and return records 
Recordset.Open SQL, Connection
'first of all determine whether there are any records 
If Recordset.EOF Then 
    MsgBox "No records returned."
Else 
'if there are records then loop through the fields 

Do While NOT Recordset.Eof   
 MsgBox Recordset("EmployeeName") & " -- " & Recordset("Salary")
  Recordset.MoveNext     
Loop

End If

MsgBox "This is the END!"

End Sub

I tested this code with the sample application I’m attaching. Just paste the code, press Add Code, then type ConnectToDB and executeStatement

I’m attaching an application showing how to do this. Look at extended form. Your users will have to make their forms extend the VBForm interface to expose their methods.

Using Events

Event handling has some issues.

All events have to be renamed (at least this is my current experience, I have to investigate further, but the .NET support for COM Events does a binding with the class names I think there’s a workaround for this but I still have not the time to test it).

In general you must create an interface with all events, rename then (in my sample I just renamed them to <Event>2) and then you can use this events.

You must also add handlers for .NET events to raise the COM events.

     #region "Events"

        public delegate void Click2EventHandler();
        public delegate void DblClick2EventHandler();
        public delegate void GotFocus2EventHandler();

        public event Click2EventHandler    Click2;
        public event DblClick2EventHandler DblClick2;
        public event GotFocus2EventHandler GotFocus2;

        public void HookEvents()
        {
            this.Click += new EventHandler(SimpleForm_Click);
            this.DoubleClick += new EventHandler(SimpleForm_DoubleClick);
            this.GotFocus += new EventHandler(SimpleForm_GotFocus);
        }

        void SimpleForm_Click(object sender, EventArgs e)
        {
            if (this.Click2 != null)
            {
                try
                {
                    Click2();
                }
                catch { }
            }
        }

        void SimpleForm_DoubleClick(object sender, EventArgs e)
        {
            if (this.DblClick2 != null)
            {
                try
                {
                    DblClick2();
                }
                catch { }
            }

        }


        void SimpleForm_GotFocus(object sender, EventArgs e)
        {
            if (this.GotFocus2 != null)
            {
                try
                {
                    GotFocus2();
                }
                catch { }
            }
        }



        #endregion

Sadly there isn’t currently a nice solution for scripting in .NET.  Some people have done some work to implement something like VBScript in .NET (including myself as a personal project but not mature enough I would like your feedback there to know if you will be interesting in a managed version of VBScript)  but currently the most mature solution I have seen is Script.NET. This implementation is a true interpreter. http://www.codeplex.com/scriptdotnet Also microsoft is working in a DLR (Dynamic Languages Runtime, this is the runtime that I’m using for my pet project of VBScript)

The problem with some of the other solutions is that they allow you to use a .NET language like CSharp or VB.NET or Jscript.NET and compile it. But the problem with that is that this process generates a new assembly that is then loaded in the running application domain of the .NET Virtual machine. Once an assembly is loaded it cannot be unloaded. So if you compile and load a lot of script you will consume your memory. There are some solutions for this memory consumption issues but they require other changes to your code.

Using other alternatives (unless you used a .NET implementation of VBScript which currently there isn’t a mature one) will require updating all your user scripts. Most of the new scripts are variants of the Javascript language.

No. There aren’t a lot of tools for this task. But you can use http://slingfive.com/pages/code/scriptConverter/

ADODB RecordSet Save in C# ASP.NET

I saw this with Francisco and this is one possible solution:

OutOfProcess In C#

In VB6 you could create an OutOfProcess instance to execute some actions. But there is not a direct equivalent for that. However you can run a class in an another application domain to produce a similar effect that can be helpful in a couple of scenarios.

This example consists of two projects. One is a console application, and the other is a Class Library that holds a Class that we want to run like an "OutOfProcess" instance. In this scenario. The console application does not necessary know the type of the object before hand. This technique can be used for example for a Plugin or Addin implementation.

Code for Console Application

using System;
using System.Text;
using System.IO;
using System.Reflection;

namespace OutOfProcess
{
    /// <summary>
    /// This example shows how to create an object in an
    /// OutOfProcess similar way.
    /// In VB6 you were able to create an ActiveX-EXE, so you could create
    /// objects that execute in their own process space.
    /// In some scenarios this can be achieved in .NET by creating 
    /// instances that run in their own
    /// 'ApplicationDomain'.
    /// This simple class shows how to do that.
    /// Disclaimer: This is a quick and dirty implementation.
    /// The idea is get some comments about it.
    /// </summary>
    class Program
    {
        delegate void ReportFunction(String message);

        class RemoteTextWriter : TextWriter
        {
            ReportFunction report;
            public RemoteTextWriter(ReportFunction report)
            {
                this.report = report;
            }
            public override Encoding Encoding
            {
                get
                {
                    return new UnicodeEncoding(false, false);
                }
            }

            public override void Flush()
            {
                //Nothing to do here
            }


            public override void Write(char value)
            {
                //ignore
            }

            public override void Write(string value)
            {

                report(value);
            }

            public override void WriteLine(string value)
            {

                report(value);
            }

            //This is very important. Specially if you have a long running process
            // Remoting has a concept called Lifetime Management.
            //This method makes your remoting objects Inmmortals
            public override object InitializeLifetimeService()
            {
                return null;
            }

        }

        static void ReportOut(String message)
        {
            Console.WriteLine("[stdout] " + message);
        }

        static void ReportError(String message)
        {
            ConsoleColor oldColor = Console.ForegroundColor;
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine("[stderr] " + message);
            Console.ForegroundColor = oldColor;
        }

        static void ExecuteAsOutOfProcess(String assemblyFilePath,String typeName)
        {
            RemoteTextWriter outWriter = new RemoteTextWriter(ReportOut);
            RemoteTextWriter errorWriter = new RemoteTextWriter(ReportError);

            //<-- This is my path, change it for your app


            //Type superProcessType = AspUpgradeAssembly.GetType("OutOfProcessClass.SuperProcess");
            AppDomain outofProcessDomain = 
                AppDomain.CreateDomain("outofprocess_test1", 
                AppDomain.CurrentDomain.Evidence, 
                AppDomain.CurrentDomain.BaseDirectory, 
                AppDomain.CurrentDomain.RelativeSearchPath, 
                AppDomain.CurrentDomain.ShadowCopyFiles);
            //When the invoke member is called this event must return the assembly

            AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(outofProcessDomain_AssemblyResolve);
            Object outofProcessObject = 
                outofProcessDomain.CreateInstanceFromAndUnwrap(
                assemblyFilePath, typeName);
            assemblyPath = assemblyFilePath;
            outofProcessObject.
                GetType().InvokeMember("SetOut", 
                BindingFlags.Public | BindingFlags.Instance | BindingFlags.InvokeMethod, 
                null, outofProcessObject, new object[] { outWriter });
            outofProcessObject.
                GetType().InvokeMember("SetError", 
                BindingFlags.Public | BindingFlags.Instance | BindingFlags.InvokeMethod, 
                null, outofProcessObject, new object[] { errorWriter });
            outofProcessObject.
                GetType().InvokeMember("Execute", 
                BindingFlags.Public | BindingFlags.Instance | BindingFlags.InvokeMethod, 
                null, outofProcessObject, null);
            Console.ReadLine();

        }

        static void Main(string[] args)
        {
            string testAssemblyPath = 
                @"B:\OutOfProcess\OutOfProcess\OutOfProcessClasss\bin\Debug\OutOfProcessClasss.dll";
            ExecuteAsOutOfProcess(testAssemblyPath, "OutOfProcessClass.SuperProcess");

        }

        static String assemblyPath = "";
        static Assembly outofProcessDomain_AssemblyResolve(object sender, ResolveEventArgs args)
        {

            try
            {
                //We must load it to have the metadata and do reflection
                return Assembly.LoadFrom(assemblyPath);
            }
            catch
            {
                return null;
            }
        }

    }


}

Code for OutOfProcess Class

using System;
using System.Collections.Generic;
using System.Text;

namespace OutOfProcessClass
{
    public class SuperProcess : MarshalByRefObject
    {
        public void SetOut(System.IO.TextWriter newOut)
        {
            Console.SetOut(newOut);
        }
        public void SetError(System.IO.TextWriter newError)
        {
            Console.SetError(newError);
        }

        public void Execute()
        {
            for (int i = 1; i < 5000; i++)
            {
                Console.WriteLine("running running running ");
                if (i%100 == 0) Console.Error.Write("an error happened");
                
            }

        }
    }
}

Visual Studio 2005. Missing Attach To Process Option

We found some machines that do not show the "Attach To Process" option.

This is very important for us, specially if you are testing the migration of an VB6 ActiveX EXE or ActiveX DLL to C#.

There is a bug reported by Microsoft http://support.microsoft.com/kb/929664

Just follow the Tool/Import Settings wizard to the end. Close and restart VS and the options will reapper.

 Also you might find that the Configuration Manager is not available to switch between Release and Build for example.

To fix this problem just go to Tools -> Options -> Projects and Solutions -> General... make sure the option "Show advanced build configurations" is checked.