OpenNetCF PreMessageFilter problem with VB.net

[Enrico Pavesi]

I create a class like this
Public Class KeyFilter
Implements IMessageFilter
Overridable Function PreFilterMessage(ByRef m As
Microsoft.WindowsCE.Forms.Message) As Boolean Implements
IMessageFilter.PreFilterMessage
Dim tasto As Integer

Select Case m.Msg
Case 786
tasto = m.WParam.ToInt32()
Select Case (tasto)
Case 193 To 196
Return True
End Select
End Select
Return False
End Function

End Class

then in the main form
InitializeComponent()
Dim Filtro As KeyFilter = New KeyFilter
ApplicationEx.AddMessageFilter(Filtro)

But this code does not trap the virtual hardware key

The same in a test C# project works.

Do someone knows why it does not work?

Thanks

 

[Daniel Moth]

Haven't looked at your code but read your question at the end. It sounds
like you have some code in C# that works and a VB version that doesn't. If
you post *both* versions we might be able to help.

Cheers
Daniel

 

[Enrico Pavesi]

The C# version is:
class KeyFilter : IMessageFilter
{
public bool PreFilterMessage(ref Message m)
{
switch(m.Msg)
{
case 0x0312:
int tasto = m.WParam.ToInt32();
switch(tasto )
{
case 193:
case 196:
return true;
break;
}

break;
}
}
return false;
}
}

and after initialize component:
KeyFilter Filtro = new KeyFilter();
ApplicationEx.AddMessageFilter(Filtro);

In the VB version it never stop at message 786 (0x0312)

Thanks

 

[Daniel Moth]

Reading this in outlook I can't see anything obvious. I presume you are
using ApplicationEx etc from a C# library and not translated them to VB,
right? If you send the project with repro steps I can have a look at it.

A couple of general comments if you want them:
1. You don't have to translate the hex to int in VB. Just use &H0312
2. Not sure why you made the interface implementation Overridable. I would
replace that with Public.
3. Case 193 To 196. Replace To with ,

Cheers
Daniel

 

[Enrico Pavesi]

The problem is that is an existing project and i can't send it.

If you have time you can post a 10 lines working vb project that trap
virtual hardkey.

In any case thanks for your hints

Regards