VBA (Visual Basic for Applications) What is Excel, just a spreadsheet? Time for Demos...

Time for demos...  Snake game  Speed game  SMS sender  Excel with movies  Sudoku solver  Etc.

What is a macro  Small computer program, that needs to run within another program.  Collection of instructions for the computer.  Automates a task for you.  What you would normally need several clicks for can now be done with one click.  Reduces the risk of errors.  Control hole computer, not just MsExcel tasks.

Recording macros  MS Office has a built-in recorder.  You can record anything you can do yourself in Excel (in theory).  You can use the recorder without knowing any VBA commands.  You can edit marcros in VBE (Visual Basic Editor)  Macros will be generated to Modules in VBE

Excercise 1  Start recording  Type your name to cell E1  Autowidth column E (doubleclick)  Stop recording  Check the macro from module1  Clear your name from cell E1 and resize the column to original width  Run the macro

Excercise 2  Start recording  Type your name to cells E1, F2 and G3  Autowidth columns E, F, and G  Stop recording  Try to shorten the code as much as possible in the module  Clear your name from cells and resize the columns to original width. Run the macro.

VBA –programming: Basic elements  If -sentence  Loop -structures  Event-Run programs  Microsoft Visual Basic Help  ’ –to comment lines in a code (apostrophe)

VBA –programming: Basic elements  If -sentence If value = true Then do this Else* do that* End If Workbook If(value=true;this;that) *Voluntary

VBA –programming: Basic elements  Enhanced If -sentence If value = 1 Then MsgBox "1.choise” ElseIf value = 2 Then MsgBox "2.choise" Else MsgBox ”No choise” End If

VBA –programming: Basic elements  Excercise III  Code a macro what reads a number from the cell A1 and multiplies it by 2 If the number is smaller than 100.  Code the program to Module and name it ExcerciseIII Sub ExcerciseIII … End Sub

Assigning macros to buttons  View – Toolbars – Form – Button  Click and draw -> Add macro

VBA –programming: Basic elements  Excercise IIIb  Assign a button to excercise III

VBA –programming: Basic elements  Enhanced If –sentence (And and Or) If value = 1 Or value = 2 Then MsgBox ”Value is 1 or 2” ElseIf value >= 2 And value <=3 Then MsgBox ”Value is between 2 and 3” Else MsgBox ”No value” End If

VBA –programming: Basic elements  Excercise IV  Code a macro what reads numbers from the cells A1 and B1.  If B1 is greater than A1 change the values. A1 gets the value of B1 and B1 gets the value of A1.  If B1 is not greater than A1, divide the numbers by 2.  The macro will be started from a button.

VBA –programming: Basic elements  Do Loop While i = 1 Do Range("A" & i).Value = i i = i + 1 Loop While i < 100  What does the loop do?

VBA –programming: Basic elements  For Next For i = 1 To 100 Range("A" & i).Value = i Next  What does the loop do?  To quit eternal loop

VBA –programming: Basic elements  Excercise V  Code a macro what types the multiplication table of number 3 to 100.  The macro will be started from a button. 1 * 3 = 3 2 * 3 = 6 3 * 3 = 9 … 100 * 3 = 300

VBA –programming: Basic elements  Excercise VI  Code a macro what types to column A, row 1 one *, to row 2 ** and finally to row 10 **********.  The macro will be started from a button. * ** *** … **********

Visual Basic Editor (VBE) Alt+F11 Place for Event-Run Macros to each Worksheet (Like Worksheet_Change ) Place for Event-Run Macros to whole Workbook (Like Workbook_Open) Place for user-defined Macros and function + global variables (Like HelloWorld)

Creating the Code. What do We Need?  Understand the MS Office object model  Access to the Visual Basic Editor VBE  Basic programming skills  Motivation

The Object Model. Why bother?  Excel (and the other Office applications) consist of a number of objects  Macro programming is actually just manipulation of these objects  When you understand the basic principle, it’s easier to learn how to program other Office programs  Press a dot after the object and you will the subobjects, properties and methods

Definition of an object  An object is a named part of a computers memory  It has certain features or properties, like some people have brown hair, others red hair etc.  It has some functionality or methods, like people are able to walk or cars able to drive  Objects can contain other objects

An example – A box Size Color Position Object properties The object might have a move method.

The Objects in Excel  The mother object is called an ”Application”  An application contains a number of workbooks.  These workbooks contain sheets.  The sheets contain ranges etc.  Application, Workbooks etc. contain many other objects, properties and methods.

Excercise VII  Try to find out who is the user of Excel (=application) at the moment.  Find a function ”at the moment”  Use MsgBox to show info to the user  Start the Macro from button

Event-run Macros  Normal Macros are run manually  Run from Buttons, Shortcuts  Event-run macros will be started automatically. They are started from an event (like Workbook_Open())  Major virus alert! If you open an application with Workbook_Open() Macro, the macro will be run.

Security levels Tools – Macros – Security If your macro doesn’t work in another computer, try to choose Medium level. Never Low!!!

Excercise VIII  Code a macro that requires a user’s name and types it to cell A1 when entering to WorkSheet 1  Use InputBox()

Excercise IX  Code a macro that automatically saves the file when closing it

Private Sub Workbook_Open() Dim Users(2) As String Dim Found as Boolean Found=False Users(0) = "Christian Brade" Users(1) = "Elvis Presley" Users(2) = "George Bush" For i = 0 To UBound(Users) If Application.UserName = Users(i) Then Found=True End If Next If Found=False Then Application.ActiveWorkbook.Close End if End Sub What does the code do?

Final advice  If you wonder how a certain operation is done, record it and look it from the code.  Place the cursor over a keyword and press F1 for help on that word.

Thank You!