How add unknown control at runtime

[José Teixeira Junior]

Hi,

How i can add one new unknown control at runtime in my form1?

Thaks.

[Morpheu]

I want create a control where i only have your type into a string.
Example:
c = "System.Windows .Forms.TextBox"

How can i do?
"José Teixeira Junior" <te************ *@stinfo.com.br > escreveu na mensagem
news:O0******** ******@TK2MSFTN GP11.phx.gbl...

Hi,

How i can add one new unknown control at runtime in my form1?

Thaks.

[Fergus Cooney]

Hi José, Morpheu,

Jose, I don't know how 'unknown' your control is but this may answer your
query. If not, tell me more about what you want to do.

Morpheu, the following will create a Control given a name such a "Button".

Public Function MakeControl (sTypeName As String) As Control
Dim sFormTypeName As String = GetType (Form).Assembly QualifiedName
sTypeName = sFormTypeName.R eplace ("Form,", sTypeName & ",")
Dim oType As Type = Type.GetType (sTypeName)
Return DirectCast (Activator.Crea teInstance (oType), Control)
End Function

This was given in answer to a similar query a week ago. For an explanation
of how it works, see
http://tinyurl.com/r393

Regards,
Fergus

[Herfried K. Wagner [MVP]]

* "José Teixeira Junior" <te************ *@stinfo.com.br > scripsit:

How i can add one new unknown control at runtime in my form1?

Please don't multipost.

--
Herfried K. Wagner
MVP · VB Classic, VB.NET
<http://www.mvps.org/dotnet>

[Tom Spink]

Maybe you should put a bit of error checking in, You are using DirectCast,
but you aren't sure whether the user has specified a type derived from
control:

Replace:

Return DirectCast (Activator.Crea teInstance (oType), Control)
With:

' ///
Dim oObj As Object = Activator.Creat eInstance(oType )

If TypeOf oObj Is Control Then
Return DirectCast(oObj , Control)
Else
oObj = Nothing
Return Nothing
End If
' ///

--
HTH,
-- Tom Spink, Über Geek

Please respond to the newsgroup,
so all can benefit

" System.Reflecti on Master "

==== Converting to 2002 ====
Remove inline declarations
"Fergus Cooney" <fi******@tesco .net> wrote in message
news:ue******** ******@TK2MSFTN GP12.phx.gbl... Hi José, Morpheu,

Jose, I don't know how 'unknown' your control is but this may answer your query. If not, tell me more about what you want to do.

Morpheu, the following will create a Control given a name such a "Button".
Public Function MakeControl (sTypeName As String) As Control
Dim sFormTypeName As String = GetType (Form).Assembly QualifiedName
sTypeName = sFormTypeName.R eplace ("Form,", sTypeName & ",")
Dim oType As Type = Type.GetType (sTypeName)
Return DirectCast (Activator.Crea teInstance (oType), Control)
End Function

This was given in answer to a similar query a week ago. For an explanation of how it works, see
http://tinyurl.com/r393

Regards,
Fergus

[Fergus Cooney]

Hi Tom,

What shall I do when I've trapped the error?

Regards,
Fergus

[Fergus Cooney]

Hi again,

Oops, window too small - missed the bit below.

If I return Nothing, the caller is going to have to check whether the
Control is Nothing instead of trapping an Exception. I think it's preferable
to throw the Exception (especially as it is done for me). This is a more
violent way to bring the error to the caller's attention, true, but I think it
is preferable.

Regards,
Fergus

[Fergus Cooney]

Hi Herfried,

Multipost? - did I miss the other one?

Regards,
Fergus

[Morpheu]

Hi Fergus,

Thank you for its help.
It worked as wanted.

Regards,
Morpheu
"Fergus Cooney" <fi******@tesco .net> escreveu na mensagem
news:ue******** ******@TK2MSFTN GP12.phx.gbl...

Hi José, Morpheu,

Jose, I don't know how 'unknown' your control is but this may answer your query. If not, tell me more about what you want to do.

Morpheu, the following will create a Control given a name such a "Button".
Public Function MakeControl (sTypeName As String) As Control
Dim sFormTypeName As String = GetType (Form).Assembly QualifiedName
sTypeName = sFormTypeName.R eplace ("Form,", sTypeName & ",")
Dim oType As Type = Type.GetType (sTypeName)
Return DirectCast (Activator.Crea teInstance (oType), Control)
End Function

This was given in answer to a similar query a week ago. For an explanation of how it works, see
http://tinyurl.com/r393

Regards,
Fergus

[Fergus Cooney]

Hi yet again Tom,

Third thoughts.

oType = GetType (SomeCrap) is likely to fail too. Before you know it the
whole thing is a mass of error handling and while it may be 'proper', it could
frighten off many a punter becaue it looks so horrendously complicated. That's
the tightrope we walk - give 'em something which will get them on their way,
or give 'em the full works which they might well reject despite it being
'perfect'. ;-)

Regards,
Fergus