Week 10
 Protecting
Code
 Protecting Worksheets
 Error Handling
 Charts
 Using
form tools
 Changing the QAT
 Revision Exercises

Run the Add Customer
form from the button on
the Data Sheet

Design Issues:
• Uses Named Range to
•
•
•

Features:
• Auto number Customer ID
• Accommodates other
ranges in the worksheet
•
place details on the sheet
Code attached to Initialize
event generates an
autonumber
The text box’s Enabled
property is set to False to
disallow editing
Need to update the named
range after input
some data below the
named range which we
don’t want to overwrite
Locking the project for viewing
means that the macros will still run
but that users will need a
password to access the code in the
editor.
 Close the file and reopen it.
 To access the code of a protected
project, from the Project Window,
double click on the appropriate
project and enter the password at
the prompt.


You can password protect
sheets using the Review tab in
excel where you can specify the
limits of the protection
 You can exclude selected cells
from the protection by
highlighting and using the
protect cells tab of the format
cells dialog


A line of code to protect the current sheet might
look like this.
ActiveSheet.Protect "password" True, True, True
Where ActiveSheet is the object and Protect the
method.
 Protect has many arguments.
 The first is the password string, followed by a
series of True/False arguments resembling the
tickbox list found in Excel.
 As with the Excel interface, by default most
options are set to True (protected) whilst a few
are false (unprotected)


Instead of always protecting the active sheet, you
might want the user to choose which sheet to
unprotect
Sub protect_choose()
Dim mySheet As Worksheet
Dim sheetName As String
sheetName = InputBox("Please type Sheet name",
"non-robust sheet selector", "sheet1")
Set mySheet = Worksheets(sheetName)
mySheet.protect “password"
End Sub
 Adapt
previous macro to protect each
sheet in turn
Sub ProtectSheets()
Dim mySheet As Worksheet
mySheet.Protect “password"
End Sub
 If
you try to run a sub to add a worksheet
named “Results” where a worksheet
named “Results” already exisits,
• Sub will stop running
• A message box containing an error code will
appear
Error handling seeks to write code that deals with
the issue and moves on to the next line
 Use
On Error Resume Next to allow the
macro to continue when an error is
encountered.
 Use Err.Number to find out if there is an
error or not. If the number property of the
Err object is 0, then no error occurred. For
example:
If err.number <> 0 Then
-- do something to cope with eventuality -End if
 Function
SheetExists
• This function uses the Err object to see if an
error occurs when a sheet is referenced, i.e. it
doesn’t exist. If an error occurs, then the Resume
command clears the error and allows the
program to continue.
• Can be used within another sub to check for a
sheet name before trying to use the name for
another sheet
Sub make_report()
Dim mysheet As Worksheet
Dim myBase As String
Dim mySuffix As Integer
Set mysheet = Worksheets.Add
myBase = "Report"
mySuffix = 1
On Error Resume Next
mysheet.Name = myBase & mySuffix
Do Until Err.Number = 0
Err.Number = 0
mySuffix = mySuffix + 1
mysheet.Name = myBase & mySuffix
Loop
End Sub
 Record
a macro to create a chart (start
with a simple column chart) in a new
sheet for the exam results on the exams
sheet
 Good example of instance where
recorded code and reference to the
object map can help
Sub MakeChart()
Selection.CurrentRegion.Select
Charts.Add
ActiveChart.ChartType = xlColumnClustered
ActiveChart.SetSourceData Source:=Sheets("Exams").Range("A1:B10")_
, PlotBy:= xlColumns
ActiveChart.Location Where:=xlLocationAsObject, Name:="Exams"
With ActiveChart
.HasTitle = True
.ChartTitle.Characters.Text = "Exam Marks"
.Axes(xlCategory, xlPrimary).HasTitle = False
.Axes(xlValue, xlPrimary).HasTitle = False
End With
ActiveChart.HasLegend = False
End Sub
 Adapt
your code to produce a pie chart
 Rename the chart
 Label the axis
 Allow the user to select the range of the
chart data

Module level variables
• Use module level variables only when two or more subs need
access to the same variable; otherwise it’s better practice to use
variables local to the procedure they are in.
• To declare a module level variable, you declare it in the
Declarations section (where the Option statements are), before
any subs.

You can use Dim as previously, but it is
recommended you use the keywords Private or
Public to determine the scope of the variable. Private
variables are accessible only to the subs in the same
module, Public variables are accessible to all the
subs in the workbook.
 An
example of a longer application
 Uses Module level variables
 Has three main Subs which call on
combinations or smaller subs
 Uses Workbook_Open event handler to
reset workbook