Microsoft Office

Part VI
Programming Excel with VBA
Monitoring a specific range for changes
The Change event occurs when any cell on the worksheet changes. In most cases, you’ll only be concerned
with changes that are made to a specific cell or range. When the Worksheet_Change event-handler procedure
is called, it receives a Range object as its argument. This Range object corresponds to the cell or
cells that changed.
Assume that your worksheet has a range named InputRange, and you want to monitor changes to this
range only. No Change event exists for a Range object, but you can perform a quick check within the
Worksheet_Change procedure. The following procedure demonstrates this:
Private Sub Worksheet_Change(ByVal Target As Excel.Range)
Dim VRange As Range
Set VRange = Range(“InputRange”)
If Union(Target, VRange).Address = VRange.Address Then
Msgbox “The changed cell is in the input range.”
End if
End Sub
This example creates a Range object variable named VRange, which represents the worksheet range that
you want to monitor for changes. The procedure uses VBA’s Union function to determine whether VRange
contains the Target range (passed to the procedure in its argument). The Union function returns an
object that consists of all the cells in both of its arguments. If the range address is the same as the VRange
address, Vrange contains Target, and a message box appears. Otherwise, the procedure ends, and nothing
happens.
The preceding procedure has a flaw. Target may consist of a single cell or a range. For example, if the user
changes more than one cell at a time, Target becomes a multicell range. Therefore, the procedure requires
modification to loop through all the cells in Target. The following procedure checks each changed cell
and displays a message box if the cell is within the desired range:
ON the CD-ROM
Private Sub Worksheet_Change(ByVal Target As Excel.Range)
Set VRange = Range(“InputRange”)
For Each cell In Target
If Union(cell, VRange).Address = VRange.Address Then
Msgbox “The changed cell is in the input range.”
End if
Next cell
End Sub
A workbook with this example is available on the CD-ROM the file is named monitor a
range.xlsm.
Using the SelectionChange event
The following procedure demonstrates the SelectionChange event. It executes whenever the user makes
a new selection on the worksheet.
Private Sub Worksheet_SelectionChange(ByVal Target _
As Excel.Range)
Cells.Interior.ColorIndex = xlNone
With ActiveCell
.EntireRow.Interior.ColorIndex = 35
752