How can I assign a .NET 4 WinForm application to the owner property of a Delphi 7 form?

Question

I need to assign a .NET 4 Winform application as the owner of a Delphi 7 form.

I have created a .dll in Delphi which contains the form. The Delphi .dll exports methods to create and display the form.

I have successfully loaded the Delphi .dll in my .NET app, and displayed the form.

Now I need to be able to assign the .NET app (or main form of the .NET app) as the owner of the Delphi form.

I have previously created a Delphi app that interops to .NET through COM, and assigns the Delphi app as the owner of the .NET forms using the following class:

public class WindowHandleWrapper : IWin32Window
{
    public HandleRef m_Handle;

    public IntPtr Handle
    {
        get
        {
            return m_Handle.Handle;
        }
    }

    public WindowHandleWrapper(IntPtr handle)
    {
        m_Handle = new HandleRef(this, handle);
    }
}

The Delphi application handle was passed as an integer to the WindowHandleWrapper constructor.

I suspect that the solution will be something similar, e.g. passing a handle to Delphi as an integer. However, the Delphi type for the Owner property of a form is TComponent. I'm just not exactly sure how to assign the .NET handle as the Delphi form's owner.

Any ideas?

Maybe OP is confused between Owner and parent... @Welton, I have to ask, why do you want the .NET winform to be the owner and not the parent of the Delphi form? — jachguate
Those reasons have nothing to do with Owner, in Delphi terms. You mean Parent. +1 @jachguate — Ondrej Kelle
@TOndrej I don't think the form wants to be parented at all. OP wants a top-level window, that doesn't appear in the taskbar. And a modal form. Problem is you need to disable the forms in the .net app. — David Heffernan
Yes, after reading his comment, perhaps he just needs to assign the winform handle to Delphi's Application.Handle. — Ondrej Kelle

Ondrej Kelle Ondrej Kelle · Accepted Answer · 2011-03-09T17:36:51

Pass your WinForm handle to the DLL as a parameter, and assign it to Application.Handle before creating and showing the form modally.

How can I assign a .NET 4 WinForm application to the owner property of a Delphi 7 form?

1 Answers