VB Migration Partner

KNOWLEDGE BASE - Forms and controls

Previous | Index | Next 

[HOWTO] Iterate over all forms of current application

Consider the following VB6 code:

        Dim frm As Form
        For Each frm In Forms
            frm.Caption  = ""

and its VB.NET translation:

        Dim frm As VB6Form
        For Each frm In Forms6
            frm.Caption = ""

As you see, references to the Form and MDIForm classes are converted to VB6Form and VB6MdiForm, respectively. Interestingly, this VB.NET code works correctly even if you add standard .NET forms to the project, because the Forms6 collection contains instances of the VB6Form and VB6MdiForm classes, but not standard .NET forms that you might have created in Visual Studio.

You can force the Forms6 collection to include native .NET forms by setting the Forms6.IncludeNetForms property to True:

        Sub Main()
        '## IncludeStatement Forms6.IncludeNetForms = True
        End Sub

Typically, when you set the Form6.IncludeNetForms property to True you also need a project-wide ChangeType pragma that tells VB Migration Partner that Form variables should be converted as System.Windows.Forms.Form variables rather than VB6Form variables:

        '## project:ChangeType Form, Form

If you omit this pragma, the controlling variable in For loops is rendered as a VB6Form variable and causes a TypeMismatch exception when it is assigned a reference to native .NET forms.

Previous | Index | Next 

Follow Francesco Balena on VB6 migration’s group on


Read Microsoft Corp’s official case study of a VB6 conversion using VB Migration Partner.

Code Architects and its partners offers remote and onsite migration services.

More details

Subscribe to our free newsletter for useful VB6 migration tips and techniques.


To learn more about your VB6 applications, run VB6 Analyzer on your source code and send us the generated text file. You will receive a detailed report about your VB6 applications and how VB Migration Partner can help you to quickly and effectively migrate it to .NET.

Get free advice

A fully-working, time-limited Trial Edition of VB Migration Partner allows you to test it against your actual code

Get the Trial

The price of VB Migration Partner depends on the size of the VB6 application, the type of license, and other factors

Request a quote

Migrating a VB6 application in 10 easy steps

Comparing VB Migration Partner with Upgrade Wizard

Migration tools: Feature Comparison Table

All whitepapers