Calling a Win32 Dll

  • Thread starter Thread starter nbotw
  • Start date Start date
N

nbotw

Hi,

I need a function call in my xml web service. I have an old win32 dll and i
have created a class to have my declaration in.

Imports System.Runtime.InteropServices

[...]

Public Class Win32
<Declaration>
End Class


Public Class myClass
Dim objW32 as new Win32()
sRet = objW32.myFunction()

[...]
End Class

If i declare the library with:
Declare Function calcular_firma Lib "c:\VInetRT\componentes\libtpv.dll" (
....params...) as short

i get ERROR: 91 "Referencia a objeto no establecida como instancia de un
objeto."
mmm ... i guess this is like: "Object not set ..."

And if i use the declaration:
<DllImport("c:\VInetRT\componentes\libtpv.dll")> _
Public Function calcular_firma( ...params... ) As Short
End Function

i get: ERROR 5: "Error: el elemento PInvoke (campo,método) debe ser
estático."
Something like "PInvoke element must be static"


Did anybody deales with this ??
Thank you in advance
 
i get: ERROR 5: "Error: el elemento PInvoke (campo,método) debe ser
estático."
Something like "PInvoke element must be static"
Click to expand...

All functions with DllImport attribute must be declared with "Shared"
keyword
 
Thank you for your answer,

I added de "Shared" keyword, but the problem remains
:(

91 "Referencia a objeto no establecida como instancia de un
objeto."
my translation: "Objet reference nos stablished as an object instance"

Best
 
Thank you for your answer,
I added de "Shared" keyword, but the problem remains
:(

91 "Referencia a objeto no establecida como instancia de un
objeto."
my translation: "Objet reference nos stablished as an object instance"
Click to expand...
Show your code, maybe we will find the solution
 
The problem were that the function needed one of the params as s fixed
length string, and when i used the migration wizard from VB6, this was
modified.

I did a little routine form dimension the string to a size needed, and it
works !
So the sentence "Declare Function" was enough, but ..

How can i define a fixed lenght string in VB.NET ??? :-)

Thank you for your help.
 
nbotw said:
The problem were that the function needed one of the params as s fixed
length string, and when i used the migration wizard from VB6, this was
modified.

I did a little routine form dimension the string to a size needed, and it
works !
So the sentence "Declare Function" was enough, but ..

How can i define a fixed lenght string in VB.NET ??? :-)
Click to expand...
Try to experiment with MarshalAs attribute
Don't know how to write it in VB, so C#: [MarshalAs(UnmanagedType.(try here
some variations), SizeConst=8)]
 
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