C# x VB6 - EventHandler

[Li]

Hello,

I have a C# class library with a form inside (ComVisible(true)) that is
instantiated by a VB6 executable. So far, so good.

I created an event at C# that has to be handled by VB6. This event works
fine when I use a VB.Net executable, but at VB6 it doesn't even recognize
that the C# form has an event.

I will be very grateful if someone could help me, showing my mistakes.

Thanks in advance.

Below is the concise code that works at VB.Net but (a similar code, written
in VB) do not at VB6:

[ComVisible(true)]
public partial class frmMain: Form
{
public event EventHandler OnDoSomething;

public void DoSomething()
{
if (this.OnDoSomething() != null)
this.OnDoSomething(this, new EventHandler());
}
}

---------------------------------------------------

Dim WithEvents frmTest As <library reference>

Public Sub TestOnDoSomething(ByVal sender as Object, ByVal e as EventArgs)
Handles frmTest.OnDoSomething
...
End Sub

 

[Frank Rizzo]

Hello,

I have a C# class library with a form inside (ComVisible(true)) that is
instantiated by a VB6 executable. So far, so good.

I created an event at C# that has to be handled by VB6. This event works
fine when I use a VB.Net executable, but at VB6 it doesn't even recognize
that the C# form has an event.

I will be very grateful if someone could help me, showing my mistakes.

As far as I understand, you have to create an interface where you define
your events and then have your class inherit from that interface.

Just as an FYI (and I am no interop expert), I was never able to achieve
stability when firing events from .NET into a VB6 client. I would get
random crashes in the VB6 ide and occasionally when running my VB6 app
as a standalone EXE.

I should point out that my C# code was a multithreaded piece and that
may have contributed to the problems.

Thanks in advance.

Below is the concise code that works at VB.Net but (a similar code, written
in VB) do not at VB6:

[ComVisible(true)]
public partial class frmMain: Form
{
public event EventHandler OnDoSomething;

public void DoSomething()
{
if (this.OnDoSomething() != null)
this.OnDoSomething(this, new EventHandler());
}
}

---------------------------------------------------

Dim WithEvents frmTest As <library reference>

Public Sub TestOnDoSomething(ByVal sender as Object, ByVal e as EventArgs)
Handles frmTest.OnDoSomething
...
End Sub