Referencing VB form in C#

[Steve]

I have a .NET windows program that has a VB.NET component and a C#
component. The VB component contains the form and handles all the UI stuff.
The C# component drives the engine that actually does all the work.

The VB component has one form called frmX. On frmX are three text boxes
(txtA, txtB, txtC) and a button (cmdAdd). When the button is clicked, the
program is supposed to add the values in txtA and txtB and display it in
txtC.

The cmdAdd_Click event instantiates a C# object called Add. I want to pass
in frmX and have the C# object extract the values in txtA and txtB and do
the calculation.

If I pass in just the text boxes then I can declare the parameters in the C#
class using

Public int DoAdd(System.Windows.Forms.TextBox txtA,

System.Windows.Forms.TextBox txtB)

But that is not what I want to do. Obviously this is only a test case and
the actually program needs to access all the elements on the form.

The question I have is, how do I pass in frmX and have access to all the
elements (text boxes, drop downs, etc.)? If I declare the parameter in C#
as

Public int DoAdd(System.Windows.Forms.Form frmF)

I have access to all the properties and method of a form, but not the
specific elements in frmX. The C# method has no clue about frmX. I have a
feeling it has to do with somehow getting a reference in the C# project or
somehow casting frmF to frmX

Any suggestions?

Thanks.

[Nicholas Paldino [.NET/C# MVP]]

Steve,

The reason this doesn't work is that you can not have circular
references between projects (nor should you). To get around this, you are
going to have to create an interface that represents the form and the
properties you want to expose on the form. This would have to be defined in
another assembly, and referenced by both the VB and C# assemblies. The VB
project would need it to know what to implement, and the C# project would
need it to know what to be passed (instead of the form instance, you get the
implementation of the interface). Then, the C# class would take this
interface as a parameter.

Also, one would question the design of passing the form instance to the
C# object. If you are going to pass specific custom UI elements (the custom
form) to an engine for processing, then you might as well include all of the
code in one project.

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com


"Steve" <sg****@convansys.com> wrote in message
news:uH**************@TK2MSFTNGP10.phx.gbl...

I have a .NET windows program that has a VB.NET component and a C#
component. The VB component contains the form and handles all the UI stuff. The C# component drives the engine that actually does all the work.

The VB component has one form called frmX. On frmX are three text boxes
(txtA, txtB, txtC) and a button (cmdAdd). When the button is clicked, the
program is supposed to add the values in txtA and txtB and display it in
txtC.

The cmdAdd_Click event instantiates a C# object called Add. I want to pass in frmX and have the C# object extract the values in txtA and txtB and do
the calculation.

If I pass in just the text boxes then I can declare the parameters in the C# class using

Public int DoAdd(System.Windows.Forms.TextBox txtA,

System.Windows.Forms.TextBox txtB)

But that is not what I want to do. Obviously this is only a test case and
the actually program needs to access all the elements on the form.

The question I have is, how do I pass in frmX and have access to all the
elements (text boxes, drop downs, etc.)? If I declare the parameter in C#
as

Public int DoAdd(System.Windows.Forms.Form frmF)

I have access to all the properties and method of a form, but not the
specific elements in frmX. The C# method has no clue about frmX. I have a feeling it has to do with somehow getting a reference in the C# project or
somehow casting frmF to frmX

Any suggestions?

Thanks.

[Peter Rilling]

By default, form controls are not public. Check the visibility for the
controls and make sure they are publicly accessible. Controls on a form are
no different then any other method or property on any other class.

"Steve" <sg****@convansys.com> wrote in message
news:uH**************@TK2MSFTNGP10.phx.gbl...

I have a .NET windows program that has a VB.NET component and a C#
component. The VB component contains the form and handles all the UI stuff. The C# component drives the engine that actually does all the work.

The VB component has one form called frmX. On frmX are three text boxes
(txtA, txtB, txtC) and a button (cmdAdd). When the button is clicked, the
program is supposed to add the values in txtA and txtB and display it in
txtC.

The cmdAdd_Click event instantiates a C# object called Add. I want to pass in frmX and have the C# object extract the values in txtA and txtB and do
the calculation.

If I pass in just the text boxes then I can declare the parameters in the C# class using

Public int DoAdd(System.Windows.Forms.TextBox txtA,

System.Windows.Forms.TextBox txtB)

But that is not what I want to do. Obviously this is only a test case and
the actually program needs to access all the elements on the form.

The question I have is, how do I pass in frmX and have access to all the
elements (text boxes, drop downs, etc.)? If I declare the parameter in C#
as

Public int DoAdd(System.Windows.Forms.Form frmF)

I have access to all the properties and method of a form, but not the
specific elements in frmX. The C# method has no clue about frmX. I have a feeling it has to do with somehow getting a reference in the C# project or
somehow casting frmF to frmX

Any suggestions?

Thanks.