Is there a way to send data from a dll to an exe, entering data from the dll into a form in the exe

Hi

The dll is activated from my exe, yes I have the source for the active x.

The problem is that I have a form in my exe that is generated from the exe not the dll.
When the exe activates the dll I need the dll to pass a string to the exe which will invoke a command in the exe to pass a string to the form.

Thanks

There are many ways to pass data from one object in your application to another.  If I understand the situation correctly the best way would be to Raise an event from the ActiveX dll.  You will then need the form to catch this event

to do this the form code wil look something like below

'EXE FORM CODE------------------------
Public withevents MyAXdllObj as AXdllObj
 
'you will need a event catch stub
Private Sub MyAXdllObj_MyEvent(byval Str as string)
  'perform actions
End Sub
 
'End EXE Form CODE--------------------------
 
'ActiveX form code --------------------------
Public event MyEvent(byval Str as String)
 
Public Sub Button1_Click()
  RaiseEvent MyEvent("This is the data I want to pass to my other form")
end sub
 
'END ActiveX Code-------------------------------------

                                              

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Hi, thanks for the help

if I pass a string how do I also add it to the form in the exe?

Basically I have a button in the dll that will create a line of text
The exe contains a function that writes that  line of text and additional data into a form in the exe. The form may or may not be open it is controlled from a function in the exe.

I don't want to click on anything in the exe except the button that loads the form in the dll. I then need the dll form to apply some processes it writes them back to the main exe as a string activating the exe write functions to the exe forms?

I presume you are calling your activex form something like below

sub SomeMethod ()
Dim AXFrm as new myAxForm
AXFrm.Show
end sub


instead of the ax form being declared with in the sub you declare it as a class level variable.  Note the WithEvents declaration is very very important.

Private WithEvents AXFrm as new myAxForm

sub SomeMethod ()
AXFrm.Show
end sub

Then you add the event stub similar to the one from my last post (This can be automatically by dropping down the Left Combobox at the top of the code page and selecting AXFrm and then dropping down the right combobox and selecting the event you want to catch)  Now when the form is shown and it raises the event then the EXE will process the string automagically.

Hi

This is the first time I've really used a dll so please bear with me.

I've decalred the link as

Private df As New edf.cls1

if I change it to private withevents df as new edf i get the error invalid use of new

in the sub I call the form by df.show_form

the show form event is part of a class in the dll.

Looks like in vb6 you can't instanciate a variable withevents immediately so

Private WithEvents df As edf.cls1 
 
Sub MyStartAXForm()
 
    set me.df = new edf.cls1
    me.df.show
 
end sub

                                              

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if I add the privtae with events I get the error object does not source automation events

You have to add the event declaration to the ActiveX form

'ActiveX form code --------------------------
'this line declares the event and causes the clase to source automation events
Public event MyEvent(byval Str as String)
'You might have to build the AX form before the exe project will recognize this change.
 
Public Sub Button1_Click()
'this is how you trigger the event (causeing the forms to talk)
  RaiseEvent MyEvent("This is the data I want to pass to my other form")
end sub
 
'END ActiveX Code-------------------------------------
                                              

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Hi, thanks for that.

I've added the declare and the exe loads the form using    
 Set df = New edf.cls1
 df.show_form

if I add me.df (or frma.df) it doesn't recognise it.

Once the form is open how do I get the code in the dll to trigger the event in the exe? without clicking on anything in the exe?

Hi
I think I'm slowly getting there, so thanks

DF is now recognised as an event in my exe form. This works to call the form

    Set frm_toolbar.df = New edf.cls1
frm_toolbar.df.show_form

I then have in my exe form
Private Sub df_MyEvent(ByVal str As String)
frm_toolbar.df.process 'this is the class in my dll
write_text 'this is a function in the exe which writes the text to the exe form
End Sub

in the dll click event I have used RaiseEvent MyEvent("kjkdskfhskdjhfskd")

but nothing happens - ???

I think you want to call the df.process method in the df code before raising the event.
Then you can place a breakpoint on the event handling sub to make sure it is getting called.
Nothing is happening because you are not passing the str to the write_text method so it isn't receiving the string that was passed across.

I think the problem may be getting the right call from the form to the class in the dll from the button click event.

In the class i have

Public Function audit_trail()

 RaiseEvent MyEvent(audit_text)

End Function

audit_text is a global string

in the button click event in the dll form I have

audit_text = "write to file"
MsgBox audit_text

Call a.audit_trail

at the top of the for I used Dim a As cls1
to link the class module. the msgbox reports the code correctly then I get error variable ot with variable not set

I understood that cls1 is the activex form
This code needs to be in the activex form not the exe

Public Function audit_trail()

 RaiseEvent MyEvent(audit_text)

End Function

For Call a.Audit_Trail you have to at some point set a to something

set a = new cls1

But again if a is your activex form you have to declare it
Dim Withevents a as cls1
otherwise you will not be waiting for the event and the exe will never know the event was raised.

sorry, I'm good at confusing myself on this one!!

the function is in the class mod of the active x not the exe - you were right the first time.

I have this in the button click of the dll form

Private Sub Command1_Click()
Set a = New cls1

audit_text = "write to file"
MsgBox audit_text

Call a.audit_trail

End Sub

this in the class mod of the dll form

Public Function audit_trail()

 RaiseEvent MyEvent(audit_text)

End Function

I get the first msgbox the appear but nothing else, I put a msgbox at the begining of the df_myevent sub in the main exe but it doesn't get this far...

I hate to confuse you more at this point, but
if you are calling a function from the exe you could also do this

----exe code---
Public Sub RunAudit ()
audit_text = "write to file"
MsgBox audit_text
set a = new cls1
Dim ReturnFromActiveX as String
ReturnFromActiveX  =  a.audit_trail("Text to Process")
'Now the processed text is stored in ReturnFromActiveX
write_text(ReturnFromActiveX)
end sub
 
Sub Write_Text (byval Text as string)
   textbox1.text = Text
end sub
 
--------ActiveX code----------
 
Public Function audit_trail(byval InText as string) as string
 
     'Process the text that came in
     dim OutText as string
      OutText = Intext & " -  I Modified the in text"
     audit_trail = outtext
 
End Function
                                              

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confusing me, not a problem I'll have a look and get back to you. Thanks

At the top of each of your forms add the following line below.  This will expose the root of most of your problems.  You aren't grasping the scope of a declaration.

If you declare a variable in a sub or function it is only available in that function to pass it to another you have to pass it to the other sub as a parameter or it goes out of scope and dissapears option explicit will not allow you to intrinsically declare a new variable by just using it and forces you to have all your variables declared in the propper scope.

Corey

Option Explicit

                                              

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in the orevious code I added a msgbox to the beginning of the code in the dll class. This showed up fine so the call a.audit_trail is going there.

The function in the dll class is
Public Function audit_trail()
MsgBox "at"
 RaiseEvent MyEvent(audit_text)

End Function

but nothing happens after that?

in the main exe I do already have option explicit, but not in the dll. I have just added it built it and rerun but it goes to the msgbox in the class function and no further, any idea what I'm just not getting ;-)

Could you post all the code in the exe related to this problem
the declaration of the AXform
the event trap stub
the method that causes the ax form to show

I've also added this to the class function call
both message boxes return fine and the contents of the variable ar being carried across but bothing actually ets actioned in the main exe?

Public Function audit_trail()
MsgBox "at"
 RaiseEvent MyEvent("test text")
 MsgBox audit_text
 
End Function

                                              

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Is the code you just posted in the main exe?

OK first the code in the exe that loads the form with no problems
Private Sub Command25_Click()

''' Show the Activex interface
   'df.show_form
    Set frm_toolbar.df = New edf.cls1
frm_toolbar.df.show_form
 
  End Sub

This is declared at the top of the form

Public WithEvents df As edf.cls1

this is the df event code with test msg boxes
Private Sub df_MyEvent(ByVal str As String)
MsgBox "even"


audit_text = frm_toolbar.df.audit_trail
MsgBox audit_text
write_audit_trail

End Sub

attached as a snippet is all the code in the form of the dll

thanks for perservering with me

Option Explicit
 
Public cs As String
Dim WithEvents a As cls1
Dim mTestForm As frmedf
 
 
 
Private Sub Command1_Click()
Set a = New cls1
 
audit_text = "write to file"
MsgBox audit_text
 
Call a.audit_trail
 
End Sub
 
Private Sub Command2_Click()
Unload Me
Set frmedf = Nothing
End Sub
 
Private Sub Form_Load()
 
frmedf.Option1(0).value = True
Call edf_options
 
End Sub
 
Private Sub Option1_Click(Index As Integer)
Call edf_options
End Sub
 
now the dll class form code
 
Option Explicit
 
Public Event MyEvent(ByVal Str As String)
 
Public Sub show_form()
 
frmedf.Show
 
End Sub
Private Sub Class_Initialize()
 
  'Set mTestForm = New frmedf
 
End Sub
 
Public Function audit_trail()
MsgBox "at"
 RaiseEvent MyEvent("test text")
 MsgBox audit_text
 
End Function

                                              

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in answer to the question just before my last post, no the previous code is in the class mod of the dll

just for clarity this is in the class mod of the dll NOT the exe

Public Function audit_trail()
MsgBox "at"
 RaiseEvent MyEvent("test text")
 MsgBox audit_text
 
End Function

Change the exe as follows

Private Sub Command25_Click()
 
''' Show the Activex interface
   'df.show_form
 
    Set frm_toolbar.df = New edf.cls1
    df = frm_toolbar.df '<--Add this line
    frm_toolbar.df.show_form
 
  End Sub

                                              

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I get the error property doesn't support this property or method relating to lin df = frm_toolbar.df
if I take it out the form loads but I get the same result as before?

Sorry I normally code in .Net and in .net you don't have to use the Set keyword.

Set df = frm_toolbar.df

ok, that run now with the set, but it doesn't pass to the exe. the df_event doesn't appear to trigger as the first msgbox doesn't activate - thanks

is mTestForm  the form you want the data go show in?

no, that was just a test er just ignor it

the text just doesn't appear to pass over. I've created a new test exe and it does the same as my original one. I just though I's try and simplify it a bit and see if I can pass the text via a string to trigger an event from the exe.

This is the code from the new exe form

Option Explicit
Public WithEvents df As edf.cls1

Private Sub Command1_Click()
    Set Me.df = New edf.cls1
 Set df = Me.df '<--Add this line
    Me.df.show_form
End Sub

Private Sub df_MyEvent(ByVal Str As String)
MsgBox "event"

Call ght
End Sub

this is the code from the new exe module (that I want to dll to trigger)

this is all the code in the dll form

Option Explicit

Public cs As String
Dim WithEvents a As cls1
Dim mTestForm As frmedf
Public Event MyEvent(ByVal Str As String)



Private Sub Command1_Click()
Set a = New cls1

audit_text = "test text"

Call a.audit_trail

End Sub

Private Sub Command2_Click()
Unload Me
Set frmedf = Nothing
End Sub

Private Sub Form_Load()

frmedf.Option1(0).value = True
Call edf_options

End Sub

Private Sub Option1_Click(Index As Integer)
Call edf_options
End Sub

and finally this is all the code in the dll class

sorry missed the code in the new exe module it is

Public Function ght()
MsgBox "test"
End Function

I think you forgot the code for the cls1

sorry, long night here is the cls code

Option Explicit

Public Event MyEvent(ByVal Str As String)

Public Sub show_form()
 
frmedf.Show

End Sub
Private Sub Class_Initialize()

  'Set mTestForm = New frmedf
 
End Sub

Public Function audit_trail()
MsgBox "at"
 RaiseEvent MyEvent(audit_text)
 MsgBox audit_text

'End Function

I also tried changing th above function to


Public Function audit_trail(ByVal InText As String) As String
 
     'Process the text that came in
     Dim OutText As String
      OutText = InText & " -  I Modified the in text"
      MsgBox OutText
     audit_trail = OutText
     
     MsgBox audit_trail

again the msgboxes work perfectly but ti doesn't go the the raise event funxtion in the exe??

Hi

If I add the call from the exe call me.df.audit trail, it accesses the msgbox in the audit function in the dll and goes to the event in the exe. But I need it to work the other way around.
I need to click on a command in the dll and cause a function in the exe to execute?
If I try to run it from the dll it goes to the 1st line in the class module function but doesn't ececute the command in the exe under the my event listing - I'm obviously missing something??

Help!! ;-)

The problem appears to be that when catching events you have to be watching the same instance of the same class that is actually firing the event.

In this case you have 2 instances of cls1.  In the exe you have Public Withevents df as cls1 and in the dll you have Public WithEvents a as cls1.  I believe you are calling code on 'a' but in the exe you are watching df.  If you make a and df the same object first you will catch the events.  This can be done by adding one of the following lines before calling the audit.

Set a = df
or
Set df = a

essencially df in the exe needs to be the same as 'a' in the dll.  You are currently creating a new cls1 object for a.



ofcourse you may need to add some extra pathing in there like

Hi

Thanks for the reply. It looks like if I click on a function in the exe it triggers the request in the dll and then executes the function in the my event of the exe.
But I need the it the other way around, when I click on the button in the dll I need it to trigger an event from the exe modules?

Hi

Thanks very much for all the help. I'm sure as I have it working one way I'll be able to move it around the other. Thanks again for all your help