Declare Dim as Integer and Boolean or Long

[Nayasoch]

I have this code which doesn't work and when I complie and run It shows Error Variable not defined and highlights the CurrentChart or ChartNum.
As I am aware Dim var1, var2 can be declared but in my case it is not working if I remove

 Dim ret As Long
    Dim formHWnd As Long

It works again perfectly .

My Code which shows errors of variables not defined.

Option Explicit
Dim ChartNum As Integer




Private Sub UserForm_Initialize()


ChartNum = 1
    UpdateChart
 
  Const C_VBA6_USERFORM_CLASSNAME = "ThunderDFrame"
    
    Dim ret As Long
    Dim formHWnd As Long
    
    
    
    'Get window handle of the userform
    
    formHWnd = FindWindow(C_VBA6_USERFORM_CLASSNAME, Me.Caption)
    If formHWnd = 0 Then
        Debug.Print Err.LastDllError
    End If


    'Set userform window to 'always on top'
    
    ret = SetWindowPos(formHWnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE Or SWP_NOSIZE)
    If ret = 0 Then
        Debug.Print Err.LastDllError
    End If
    
End Sub




Private Sub UpdateChart()


    Set CurrentChart = Sheets("Graph1").ChartObjects(ChartNum).Chart
    CurrentChart.Parent.Width = 380
    CurrentChart.Parent.Height = 260


'   Save chart as GIF
    Fname = ThisWorkbook.Path & Application.PathSeparator & "temp.gif"
    CurrentChart.Export FileName:=Fname, FilterName:="GIF"


'   Show the chart
    Image1.Picture = LoadPicture(Fname)
End Sub

Any help would be rightly appreciated.

 

[JoeMo]

Because you have used Option Explicit above your procedures, you must dimension all variables in those procedures. It looks like you have not dimensioned the variable CurrentChart in the last procedure.

 

[Nayasoch]

So what might be the solution , should i remove option Explicit??

 

[Nayasoch]

Well That worked, I don't know why but as I removed Option explicit ....It worked as smoothly as butter. Thanks JoeMo.

 

[JoeMo]

So what might be the solution , should i remove option Explicit??

You can, but better practice is to declare the variable(s) you have not yet declared.

 

[Rick Rothstein]

So what might be the solution , should i remove option Explicit??

No! Do not remove it... you should always use it, especially if you are going to do any VBA coding where the results matter. Let me give you an example of the problem if Option Explicit is not declared.

Sub Par()
  Collections = 1000
  If SomethingImportant = True Then Col1ections = Collections * 2
  '
  '  more code here that use the value in Collections
  '
End Sub

It is somewhat easy to see the problem given the font used by this forum (I "accidentally" typed a one instead of the lower case letter L), but copy/paste the above code into a VBA module and see if the problem is as obvious to spot there. Now, the problem is that without Option Explicit, the calculation after the Then statement will take place without error, but the Collections variable will not be updated if SomethingImportant is True and every calculation after this point in the code will be wrong, but you will not know that because no error occurred. With Option Explicit, on the other hand, VB will stop your code and tell you Col1ection has not been declared. You will look at it and know it must be spelled wrong because you know you declared Collection already. This will help guide you to finding the spelling error allowing you to fix the problem. This is a simple example... 0 (zero) and the letter O also look a lot alike. And, of course, you could simply make a plain typing error somewhere in your code... it may be easy to spot the typo if you knew it was there, but if no error is generated because Option Explicit was not used, you would not know to look for it. Bottom line... always use Option Explicit.