Converting a String into a Function  (VB.NET)

Posted on 2003-02-26
Medium Priority
Last Modified: 2010-05-01

I have an problem. I have an string datatype like this.

Dim sFunctionString as String
sFunctionString = "Msgbox(" & sMessage & ")"

so how can i convert this string to an executable function and call it?

Thank you for your support

Joerg Bonsack
Question by:Joerg_Bonsack
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Expert Comment

ID: 8025966
In VB, you can't.

YOu'd need to do somthing like

If left$(sFunctionString, 6) = "Msgbox" Then
   Msgbox ...
end if

And that kind of defeats the purpose

Expert Comment

ID: 8026297
I dont think you can in VB, definately could in ANSI C, If i can get a hold of the code perhaps I could work some conversion or other but I wouldnt hold out too much hope.

Could you not just parse the string with an if/case statement for each possibilty as below ?

Dim strTemp As String
Dim strProcedure As String
Dim strParameter As String
Dim pointer As Integer

strTemp = "msgbox(""Hello"")"
pointer = InStr(1, strTemp, "(", vbTextCompare)

strProcedure = Left(strTemp, pointer - 1)

strTemp = Right(strTemp, Len(strTemp) - pointer)
pointer = InStr(1, strTemp, ")", vbTextCompare)
strTemp = Left(strTemp, pointer - 1)

strParameter = Replace(strTemp, Chr(34), "", 1, , vbTextCompare)

If strProcedure = "msgbox" Then
    MsgBox strParameter
End If

Expert Comment

ID: 8026858
How many different commands are you trying to place in a string like that?

If it is always msgbox then there are better ways.

If there are a limited number of commands, you may consider a case statement instead of IF THEN ELSE.

With a little more info, I may be able to offer better help.
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Author Comment

ID: 8026962
That is not the problem with if then else etc.

Let me explain it again:

I have a Active Searching Routine which is descibe like so:
'The namespace is Searcher
' The Properties are: folder
'                      item(smth.)

Public function Count_Sub_Folders(nCounter as integer)
Dim sFunction_Call as string
Dim nResult as integer
sFunction_Call = "Searcher."    
      for x = 1 to nCounter
           sFunction_Call = sFunction_Call & ".Folder.Item(" & nCounter & ")"
     next nCounter
sFunction_Call = sFunction_Call & ".count()"
'Here comes the problem:
' I have a builded string like:
NResult= 'Here i need the function call'
end Function

The function must be filled dynamiclly with properties.

Thank you for your support

Expert Comment

ID: 8064728
Try this...

On a form or in a class (cannot do in a module)

' Call string function
Call CallByName(Me, sFunctionString, vbMethod)

Example on a form:

Public Sub Test(byVal sMessage as string)

 Call MsgBox(sMessage)

End Sub

Private Sub cmdButton_Click()

Call CallByName(Me, "Test", vbMethod, "Message 2B Displayed")

End Sub

Expert Comment

ID: 8940451
This old question needs to be finalized -- accept an answer, split points, or get a refund.  For information on your options, please click here-> http:/help/closing.jsp#1 
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LVL 49

Expert Comment

ID: 8973023
Joerg_Bonsack, an EE Moderator will handle this for you.
Moderator, my recommended disposition is:

    Save as PAQ -- No Refund.

DanRollins -- EE database cleanup volunteer

Accepted Solution

Computer101 earned 0 total points
ID: 9668040
PAQed - no points refunded (of 75)

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