In some circumstances you might notice the following behavior in a migrated .NET program: a window opens a modal dialog form but when the user closes the modal form the parent window doesn’t receive the input focus and another window – possibly from a different application – becomes the foreground window.

While the causes for this behavior remain unknown, we have added a couple properties to the VB6Form class that aim to reduce (and hopefully eliminate) this problem. These properties are OwnerWindowHandle (which permits to specify the parent window of a modal window) and ResetForegroundParentForm ( if true, the support library attempts to give the input focus back to the parent window when the modal window closes). The typical .NET code that uses these properties looks like this:

    ' VB.NET
    Dim frm As New Form1
    frm.ResetForegroundParentForm = True
    frm.OwnerWindowHandle = Me.Handle
    frm.Show(1)
 
    // C#
    Form1 frm = new Form1();
    frm.ResetForegroundParentForm = true;
    frm.OwnerWindowHandle = this.Handle;
    frm.Show(1);

In most cases the assignment to the OwnerWindowHandle property is optional, because the support library can deduce this value by itself. The assignment to the ResetForegroundParentForm property is also optional: if you want to apply it to all the modal window in your migrated project you can just assign True to the VB6Form.ResetForegroundParentForms static property (notice the plural):

    VB6Form.ResetForegroundParentForms = True