asked on

How to User a existed Control as a parameter of a function?

I write a function, the type of one of the parameter is ComboBox , like this:
Private Sub AddDataToList(ByRef cmbTarget As ComboBox, ByRef strSql As String)
.....
end sub

But How can I use a existed Control as a parameter when use this function? for example. I have a ComboBox in the form named cmbTypes, when I use it as "call AddDataToList(cmbTypes, strSql)", the compiler warns me with the message "the cmbTypes is not the name of a variable". How can I do?

Ryan Chong

If the AddDataToList is in a module, it should declare as Public not private. However, make sure the ComboBox name passed to the Sub is absolute correct.

* In additional (just in case), use ByVal instead of ByRef.

falconew

I think your code is correct. Please copy paste your detail code here.

Thanks.

ventond

ByVal would make a copy of the combo box in memory and discard it when the sub ended. Probably not very usefull when you want to update the original.

Iaskyou

ASKER

that are all codes.
the error occurs at "call AddDataToList(cmbTypes, strSql)".
cmbTypes is the name of the control which has existed in the form, not the declared variable.

ventond

Are you sure you have this:
call AddDataToList(cmbTypes, strSql)

and not this?:
AddDataToList(cmbTypes, strSql)

Iaskyou

ASKER

this is all codes:
--------------------------------------------------------
'//////////////////////////////////////////////////////////Option Explicit ' to enable proper syntax checking

' variable declarations with form scope
Private Sub Form_Load()

'cmb1BookTypes is name of a existed ComboBox at Form
Call AddDataToList(cmb1BookTypes, strSql)'Err Occurs
Call AddDataToList(cmb2BookTypes, strSql)
End Sub

Private Sub AddDataToList(ByRef cmbTarget As ComboBox, ByRef strSql As String)
Dim resData As New ADODB.Recordset
Dim i As Integer

cmbTarget.Clear
On Error GoTo DBErrHandle

'gblDBConn opened at gloabl.bas
resData.Open strSql, gblDBConn
i = 0
While Not resData.EOF
cmbTarget.AddItem (resdate(1))
cmbTarget.ItemData(i) = CLng(resdate(0))
i = i + 1
resData.MoveNext
Wend
resData.Close
If i > 0 Then
cmbTarget.ListIndex = 0
End If

DBErrHandle:
MsgBox Err.Description
Set resData = Nothing
End Sub

ventond

Is it possible that your combobox is not a standard combo box? Perhaps a DbComboBox?

MCummings111400

Try using Me.cmb1BookTypes...

Call AddDataToList(Me.cmb1BookTypes, strSql)

falconew

I have tried your code on my computer and it runs normally, no warning message. Are you sure the error is on the combo box? Have you debug your code?

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falconew

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ventond

The problem here is that your code that you have given us works. If it is stand alone. There is something else in your project that is causing this code in your project to fail. Right click on the cmb1BookTypes in your call statement. Choose Definition. If it takes you anywhere, chances are that is the problem.

MCummings111400

Also double check the name of the control on your form. You may have misstyped the name in the properties box in the form design.

DanRollins

Hi Iaskyou,
It appears that you have forgotten this question. I will ask Community Support to close it unless you finalize it within 7 days. I will ask a Community Support Moderator to:

Accept falconew's comment(s) as an answer.

Iaskyou, if you think your question was not answered at all or if you need help, just post a new comment here; Community Support will help you. DO NOT accept this comment as an answer.

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SpideyMod

per recommendation

SpideyMod
Community Support Moderator @Experts Exchange