1. The animation is already done for you; just copy and paste the slide into your existing presentation. Dony Pranadiyanta, ST

2. VBA - Excel VBA is Visual Basic for Applications The goal is to demonstrate how VBA can be used to leverage the power of Excel VBA syntax and usage the Excel VB programming environment the Excel object model an application

3. VBA - Excel What advantage is there in using VBA extend Excel – new functions makes it possible to use the Execl GUI environment makes it possible to respond to events (mouse, …) makes Windows programming API accessible Excel can be used to control Automation servers (other software components that expose an API through COM) by understanding how to use the Excel object model with VBA it is a small step to using Excel as an Automation server (controlled by other program)

4. VBA - Excel In order to run VBA code your security settings must be properly set Tools | Macro | Security… At least Medium security must be set – each macro will require user verification to run Signed code can be run in all cases

5. Objectives Create a macro using the macro recorder Work with the Project Explorer and Properties window of the VBA Editor Edit a sub procedure Run a sub procedure Work with VBA objects, properties, and methods Create an input box to retrieve information from the user New Perspectives on Microsoft Office Excel 2007 5

6. Objectives Create and run If-Then control structures Work with comparison and logical operators Create message boxes Customize the Quick Access Toolbar Customize Excel New Perspectives on Microsoft Office Excel 2007 6

7. Developing an Excel Application New Perspectives on Microsoft Office Excel 2007 7 If the Excel Developer tab is not on the Ribbon, click the Office Button, click the Excel Options button, click Popular in the Excel Options dialog box (if necessary), click the Show Developer tab in the Ribbon check box to insert a check mark, and then click the OK button

8. Working with the Visual Basic Editor In the Code group on the Developer tab, click the Macros button Click the macro name in the Macro name box, if necessary, and then click the Edit button New Perspectives on Microsoft Office Excel 2007 8

9. Working with the Visual Basic Editor A project is a collection of macros, worksheets, data-entry forms, and other items that make up the customized application you’re trying to create Project Explorer is the window in the Visual Basic Editor that displays a hierarchical list of all currently open projects and their contents The Project Explorer window is dockable An object is any element within the Excel working environment such as a worksheet, cell, workbook, or even Excel itself New Perspectives on Microsoft Office Excel 2007 9

10. Working with the Visual Basic Editor A property is an attribute of an object that defines one of its characteristics, such as its name, size, color, or location on the screen You can view a list of properties for any object in the Properties window A module is a collection of VBA macros The Code window displays the VBA macro code associated with any item in Project Explorer New Perspectives on Microsoft Office Excel 2007 10

11. Working with the Visual Basic Editor New Perspectives on Microsoft Office Excel 2007 11

12. Working with Sub Procedures A sub procedure performs an action on your project or workbook, such as formatting a cell or displaying a chart A function procedure returns a value A property procedure is used to create custom properties for the objects in your project Syntax refers to the set of rules that specify how you must enter certain commands so that VBA interprets them correctly A comment is a statement that describes the behavior or purpose of a procedure, but does not perform any action New Perspectives on Microsoft Office Excel 2007 12

13. Working with Sub Procedures New Perspectives on Microsoft Office Excel 2007 13

14. Referring to Objects VBA is an object-oriented programming language, in which tasks are performed by manipulating objects New Perspectives on Microsoft Office Excel 2007 14

15. Referring to Objects Objects are often grouped into collections, which are themselves objects, called collection objects New Perspectives on Microsoft Office Excel 2007 15

16. Referring to Objects VBA organizes objects and object collections in a hierarchy with the Excel application at the top and the individual cells of a workbook at the bottom New Perspectives on Microsoft Office Excel 2007 16

17. Referring to Objects New Perspectives on Microsoft Office Excel 2007 17

18. Applying Methods A method is an action that can be performed on an object, such as closing a workbook or printing the contents of a worksheet New Perspectives on Microsoft Office Excel 2007 18

19. Working with Variables and Values A variable is a named element in a program that can be used to store and retrieve information Every variable is identified by a unique variable name Dim variable as type New Perspectives on Microsoft Office Excel 2007 19

20. Retrieving Information from the User New Perspectives on Microsoft Office Excel 2007 20

21. Working with Conditional Statements New Perspectives on Microsoft Office Excel 2007 21

22. Working with Conditional Statements New Perspectives on Microsoft Office Excel 2007 22

23. Working with Conditional Statements New Perspectives on Microsoft Office Excel 2007 23

24. Working with Conditional Statements New Perspectives on Microsoft Office Excel 2007 24

25. Creating a Message Box MsgBox Prompt, Buttons, Title New Perspectives on Microsoft Office Excel 2007 25

26. VBA – The Basics Data types Integer2 byte integer Long4 byte integer Single4 byte floating point Double8 byte floating point Currency8 byte real Stringupto 64K characters Byte1 byte Boolean2 byte true or false Date8 bytes Object4 bytes – an object reference Variant16 bytes + 1 byte / character

27. Variables Declare by Dim Better to use Data Types: Dim amount As Double Dim year As Integer Dim name As String Other data types: Boolean, Byte, Currency, Date Default (no type) is Variant

28. Variable (cont’d.) % - integer& - long integer ! - single# - double @ currency$ - string anIntegerValue% =3, aString$ = "hallo" Can modify with scope (outside procedure) Private I As Integer Public billsPaid As Currency Make values permanent Static yourName As String Multiple variables Private test, amount, J As Integer

29. Constants [Public|Private] Const constantName [As type] = expression Public Const PI = 3.1, NumPLANETS = 9 Const PI2 = PI * 2 Const RELEASE = #1/1/99/#

30. VBA – The Basics The variant data type is special – a variant can hold any type of data A variable declared as variant (the default) can hold anything The actual type of the data is kept in the data It adds flexibility but at a cost – it requires more processing at compute time to determine what it is and how to handle it

31. VBA – The Basics Variables must start with a letter can contain _ and numbers cannot exceed 255 characters in length Within a procedure declare a variable using If a variable is not declared it will be created when used, the type will be Variant Use Option Explicit in the declarations section to require declaration of variables VBA variables have scope restrictions variables declared in a procedure are local to that procedure variables declared in a module can be public or private Dim variable Dim variable As type

32. VBA – The Basics String variables The first form is variable length The second form is limited to 50 characters the variable will be space filled if string is < 50 characters the string will be truncated if the contents are > 50 characters the Trim and RTrim functions are useful for working with fixed length strings Boolean variables contain either True or False Dim variable As String Dim variable As String * 50

33. VBA – The Basics The Object type is used to store the address (a reference) of an object this form can be used for any object this is referred to as late-binding, the object types are checked at runtime (slower) The declaration of a specific object is this form will only store Excel Worksheet objects, an attempt to put anything else into it will result in an error this is referred to as early-binding, the object types are checked at compile time (faster) Dim variable As Object Dim variable As Worksheet

34. VBA – The Basics Arrays are declared using Arrays can be multidimensional The lower bound starts at zero can explicitly specify lower bound can use Option Base command to reset to something other than 0 The last form above is a dynamic array – it must be dimensioned using ReDim before it can be used Use ReDim Preserve to retain any existing entries in array - only the upper bound of array can be changed Dim A (1 To 10) As Double Dim B (1 To 10, 1 To 10) As Double Dim C (4,4,4) As Integer Dim D () As Double Option Base 1

35. VBA – The Basics Constants are declared using Constants have the same scope limitations as variables Const pi = 3.14159 Const pi As Double = 3.14159

36. VBA – The Basics User defined data types can only be defined in the declarations section of a Module can be Public or Private in scope Declare variable with this type Referencing fields Public Type SystemInfo CPU As Variant Memory As Long ColorBits As Integer Cost As Currency PurchaseDate As Date End Type Dim MySystem As SystemInfo MySystem.CPU = “Pentium” If MySystem.PurchaseDate > #1/1/2006# Then … End If

37. VBA – The Basics Watch out for it is equivalent to Dim a, b, c As Integer Dim a As Variant Dim b As Variant Dim c As Integer

38. VBA – The Basics Objects VBA can use pre-defined objects – such as intrinsic Excel objects VBA can create user-defined objects – Class Modules Declaring a variable to contain an object the first form declares that the variable will contain a reference to an object of the named class the second form declares the variable then creates an instance of the class To instantiate a class Dim variable As class Dim variable As New class Set variable = New class

39. VBA – The Basics Objects To declare a variable that will refer to an instance of the Excel Worksheet class To put a reference into it This fragment will print the name of the worksheet “Sheet1” Dim ws1 As Worksheet Set ws1 = Worksheets(“Sheet1”) Dim ws1 As Worksheet Set ws1 = Worksheets("sheet1") Debug.Print ws1.Name

40. VBA – The Basics Objects - Collections There is a special form of objects known as Collections They contain references to other objects and collections It is the mechanism by which the object hierarchy is defined By convention, collection names are usually plural Workbooks – list of Workbook objects Worksheets – list of Worksheet objects Range – list of objects that represent cells, columns, rows The following example iterates through Workbooks collection For Each ws In Worksheets Debug.Print ws.Name Next

41. VBA – The Basics Statements VBA implements common programming statements logical statements looping statements expressions

42. VBA – The Basics Logical statements The If Then Else statement is the basic logic test If a>10 Then … End If If a>10 Then … ElseIf a<0 Then … Else … End If If a>10 Then … Else … End If

43. VBA – The Basics Logical statements The Select statement can be used to replace a multi-way if statement Select Case expression Case expr1 … Case expr2 … Case Else … End Select

44. VBA – The Basics Loop statements Various Do loop forms Do While expr … Loop Do Until expr … Loop Do … Loop While expr Do … Loop Until expr

45. VBA – The Basics Loop statements A common For loop For i=1 To 10 Debug.print i Next i For i=1 To 10 Step 2 Debug.print i Next i

46. VBA – The Basics Loop statements Another For loop Commonly used to iterate through collections For Each element In group … Next element For Each ws In Worksheets Debug.Print ws.Name Next

47. VBA – The Basics Procedures Procedures in VBA are either Macros or Functions a macro does not return a value a function will return a value Property functions (Get and Let) are used in Class Modules to provide access to private properties Sub Name() … End Sub Function Name() As Double … End Sub

48. VBA – The Basics Dealing with runtime errors The On Error statement will trap errors The error name is a label in the code In the error code a Resume statement will cause the statement that caused the error to be executed again In the error code a Resume Next statement will restart execution on the statement after the one that caused the error … On Error GoTo label … On Error GoTo check … check: …

49. VBA – Programming Environment Excel (all Office components) have a VBA programming environment, VBIDE It consists of the Visual Basic Editor an Object Browser debugging support These are accessed from the Excel menu There is also a set of CHM files that document the components and object models of Office (for version 10) the Excel file is named VBAXL10.CHM XLMAIN10.CHM is the main help file for Excel and contains VBAXL10.CHM within it each version of Office has its own set of files http://www.ae.gatech.edu/classes/ae6382/documents/MS_Scripting/Office10/

50. VBA – Programming Environment To start the Visual Basic Editor from Excel select Tools | Macro | Visual Basic Editor

51. VBA – Programming Environment Once in the VB Editor – to start the Object Browser select View | Object Browser

52. VBA – Programming Environment In the Object Browser to select only the Excel objects use the pull down menu at the upper left

53. VBA – Programming Environment To view information on the Worksheet object and its Name property

54. VBA – Programming Environment The usual way to create code is to double-click on one of the Worksheet or Workbook objects in the Project Explorer and enter the code.

55. VBA – Programming Environment By using the menu item Insert it is possible to add other types of procedure containers forms (GUI) modules for library-like procedures class modules for defining classes

56. VB Edit Window Project Explorer Property Inspector Code Window Edit Window Options

57. VBA – Excel Objects The top level object is the Workbook. A workbook corresponds to an open XLS file Each Workbook object is kept in the Workbooks collection To open a workbook file use Dim wb = Workbooks.Open(“filename) To close a workbook use the Close method on the workbook object or the Workbooks entry Other methods for use with Workbooks are Save and SaveAs

58. VBA – Excel Objects The Worksheet corresponds to a Sheet Each Worksheet object is kept in the Worksheets collection To add a single new Worksheet Dim ws = Worksheets.Add(count:=1) ws.Visible = False will hide the sheet ws.Delete will delete the sheet Worksheets(“Sheet1”).Delete will delete a sheet

59. VBA – Excel Objects The Range object (collection) corresponds to a set of cells To set a value into a cell Worksheets(“Sheet1”).Range(“A5”).Value = 3.14159

60. Data Exchange between Excel and Visual Basic

61. Outline Data exchange between Excel and Visual Basic. Programming VB in Excel

62. Exchange data with.csv file.csv file is “comma separated value” file..csv file is plain text file..csv file can only save one worksheet. For multiple worksheets in a workbook, you need to use several.csv files. You need do some editing to remove titles or labels before you use VB to read it.

63. Example

64. Code Private Sub Command1_Click() Dim payment(1 To 50) As Single, commission(1 To 50) As Single Dim index As Integer Open App.Path & "\commission.csv" For Input As #1 index = 1 Do While Not EOF(1) Input #1, payment(index), commission(index) index = index + 1 Loop Close #1 End Sub

65. Using VB in Excel Excel uses a special version of Visual Basic, which is called Visual Basic for Application (VBA) User can use VBA to create customized Excel function (VBA procedures), which can be much more powerful than the build-in Excel functions.

66. Security issues VBA procedures in Excel is also called Macros. Macros are two-edged swords. Macros viruses are malicious VBA procedures.

67. Setting the security level

68. Security Level High (default) Medium. We should set the security to this level to run our VBA procedure. Low (not recommended)

69. Medium level security If you set the security level to medium, every time you open a Excel file containing macro, Excel will ask you if you want to enable the macro.

70. Example

71. VBA function code Function Comm(Sales_V As Single) as Single If Sales_V =500 and Sales_V =1000 and Sales_V =200 and Sales_V =5000 Then Comm=Sales_V*0.15 End If End Function

72. Edit VBA program in Excel

73. Insert modules The VBA procedure should be defined in a module. If you don‘t have an existing module, create one by using the insert->Module menu.

74. Write code in visual basic editor

75. Final result

76. Passing a range of cells to VBA procedure The previous example shows how to pass one value to a VBA function. However, in Excel it is possible to pass several cells to a build-in function. E.g. SUM(a5:a7) We call a5:a7 is a range. User defined VBA function can also get a range of cells as input.

77. Data type: range VBA defines a specific data type: range Range is just like a object: it has properties. Important properties of range Count : How many cells in the range Value : Value of the cell (it works when range refers to only one cell)

78. Accessing individual cells We use a special form of For…Next loop to access each cell in a range Function meanvalue(InputRange As Range) As Single Dim cl As Range For Each cl In InputRange ‘some code here to get the value ‘cl.value keep the value of the cell Next cl End Function Red word are key word in Visual Basic

79. Program task Define a VBA function that calculate the average of a range of cells. We define the function’s name as meanvalue.

80. code Function meanvalue(InputRange As Range) As Single Dim cl As Range ‘cl is used to get individual cell Dim index As Integer, sum As Long index = 1 ReDim inputarray(1 To InputRange.Count) As Single For Each cl In InputRange inputarray(index) = cl.Value ‘save cell value into array index = index + 1 Next cl sum = 0 For i = 1 To InputRange.Count sum = sum + inputarray(i) Next meanvalue = sum / InputRange.Count End Function

81. Use your defined VBA function