Modifying a spreadsheet using a VB macro - excel

Question

I have two spreadsheets... when one gets modified in a certain way I want to have a macro run that modifies the second in an appropriate manner. I've already isolated the event I need to act on (the modification of any cell in a particular column), I just can't seem to find any concrete information on accessing and modifying another spreadsheet (this spreadsheet is located on a different LAN share also... the user has access to both, though).
Any help would be great. References on how to do this or something similar are just as good as concrete code samples.

Answer 1

In Excel, you would likely just write code to open the other worksheet, modify it and then save the data.
See this tutorial for more info.
I'll have to edit my VBA later, so pretend this is pseudocode, but it should look something like:
Dim xl: Set xl = CreateObject("Excel.Application")
xl.Open "\\the\share\file.xls"
Dim ws: Set ws = xl.Worksheets(1)
ws.Cells(0,1).Value = "New Value"
ws.Save
xl.Quit constSilent

Answer 2

You can open a spreadsheet in a single line:
Workbooks.Open FileName:="\\the\share\file.xls"
and refer to it as the active workbook:
Range("A1").value = "New value"

Answer 3

After playing with this for a while, I found the Michael's pseudo-code was the closest, but here's how I did it:
Dim xl As Excel.Application
Set xl = CreateObject("Excel.Application")
xl.Workbooks.Open "\\owghome1\bennejm$\testing.xls"
xl.Sheets("Sheet1").Select
Then, manipulate the sheet... maybe like this:
xl.Cells(x, y).Value = "Some text"
When you're done, use these lines to finish up:
xl.Workbooks.Close
xl.Quit
If changes were made, the user will be prompted to save the file before it's closed. There might be a way to save automatically, but this way is actually better so I'm leaving it like it is.
Thanks for all the help!

Answer 4

Copy the following in your ThisWorkbook object to watch for specific changes. In this case when you increase a numeric value to another numeric value.
NB: you will have to replace Workbook-SheetChange and Workbook-SheetSelectionChange with an underscore. Ex: Workbook_SheetChange and Workbook_SheetSelectionChange the underscore gets escaped in Markdown code.
Option Explicit
Dim varPreviousValue As Variant ' required for IsThisMyChange() . This should be made more unique since it's in the global space.
Private Sub Workbook-SheetChange(ByVal Sh As Object, ByVal Target As Range)
' required for IsThisMyChange()
IsThisMyChange Sh, Target
End Sub
Private Sub Workbook-SheetSelectionChange(ByVal Sh As Object, ByVal Target As Range)
' This implements and awful way of accessing the previous value via a global.
' not pretty but required for IsThisMyChange()
varPreviousValue = Target.Cells(1, 1).Value ' NB: This is used so that if a Merged set of cells if referenced only the first cell is used
End Sub
Private Sub IsThisMyChange(Sh As Object, Target As Range)
Dim isMyChange As Boolean
Dim dblValue As Double
Dim dblPreviousValue As Double
isMyChange = False
' Simple catch all. If either number cant be expressed as doubles, then exit.
On Error GoTo ErrorHandler
dblValue = CDbl(Target.Value)
dblPreviousValue = CDbl(varPreviousValue)
On Error GoTo 0 ' This turns off "On Error" statements in VBA.
If dblValue > dblPreviousValue Then
isMyChange = True
End If
If isMyChange Then
MsgBox ("You've increased the value of " & Target.Address)
End If
' end of normal execution
Exit Sub
ErrorHandler:
' Do nothing much.
Exit Sub
End Sub
If you are wishing to change another workbook based on this, i'd think about checking to see if the workbook is already open first... or even better design a solution that can batch up all your changes and do them at once. Continuously changing another spreadsheet based on you listening to this one could be painful.