Basic Question: VB DLL Called from VB? 2

[swatman]

Hi,

a basic question this one, I'm sure...

I wish to put code in a VB DLL. It is declared as Public thus:

Public Sub mysub()
MsgBox "Hello world"
End Sub

In the client app, it is declared as:
Public Declare Sub mysub Lib "testdll" ()

However I get error 453, entry point not found. I have done a VC++ DLL in VB, and thought VB DLL to VB should be easier.

Can someone help?

thanks...

 

[zemp]

Set up a class in your dll with the function you described above. Then from VB declare the class (of the dll) as a variable

dim oClass as dllname.dllclass

Create a new instance of this variable.

Set oClass =New dllname.dllclass

Then call the procedure, qualified with the class variable.

oClass.mysub

Thanks and Good Luck!

zemp

 

[strongm]

Follow zemp's advice; VB creates COM DLLs, not 'classic' DLLs

 

[swatman]

Zemp/strongm,

thanks!

 

[swatman]

thanks Zemp,

I have been banging my head on this one for a week.

So, VB DLLs will not export functions and Subs. Rather, only methods of Classes may be exported.

Something else I found, it seems that you do not need to instantiate an instance of your DLL service to call the method.

ie in the DLL, I have a class with:
Public Sub mySub()
msgbox "Hello World"
end Sub

It can be called from the client App as below:

sub Commmand_Click()
myObj.mySub
' or...
mySub
end Sub

So even if it does not allow you to create traditional 3GL functions and subs, the methods can be called as if they were functions or subs.

 

[zemp]

Interesting, never tried it without the qualifying object variable. Probably a case of 'if it ain't broke don't fix it'.

Thanks and Good Luck!

zemp

 

[strongm]

Be careful with non-qualification...