Definitive Guide to Excel VBA, Second Edition

MICHAEL KOFLER TRANSLATED BY DAVID KRAMER

APress Media, LLC

Definitive Guide to Excel VBA, Secend Edition Copyright ©2003 by Michael Kofler Originally published by Apress in 2003

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Contents at a Glance

Preface ............................................................ ....................................................... xzzz The Idea Behind This Book ............................................................................. xv

Part One An Intuitive Approach .................................................................................. 1

Chapter 1

Chapter 2

Part Two

Writing Your First Macro ................................................... 3

What)s New in Excel 2000 ................................................ .47

Fundamentals ...................................................................................................... 65

Chapter 3 Chapter 4 Chapter 5 Chapter 6

Chapter 7

Chapter 8

Part Three

The Development Environment ........................................... 67

VBA Concepts ............................................................................ 85

Techniques of Programming ............................................. 185

Debugging) Protection When Errors Arise ............... 371

Forms (Microsoft Forms Library) ................................ 387

Menus and Toolbars ............................................................. 457

Application ...................................................................................................... 493

Chapter 9 Templates) Smart Forms .................................................... 495

Chapter 10 Charts and Drawing Objects (Shapes) ........................ 527

Chapter 11

Chapter 12

Chapter 13 Chapter 14

Part Four

Data Management in Excel ............................................... 569

Access to External Data .................................................. 619

Data Analysis in Excel .................................................... 687

VBA Programming for Pros ................................................ 731

Reference ........................................................................................................... 791

Chapter 15 Object Reference ................................................................. 793

Appendix Excel 2003 Beta 2 ................................................................ 863

References ............................................................................................................ 879

Index ...................................................................................................................... 881

üi

Contents

Preface ........................................................................................................... ........ xiii

The Idea Behind This Book ............................................................................. xv

Part One An Intuitive Approach .................................................................. 1

Chapter 1 Writing Your First Macro .......................................... 3

1.1 Definition of Terms .................................................................................. 4

1. 2 What Is Visual Ba sie for Applications? ......................................... 6

1.3 Linking a Custom Style with a Tool .................................................. 9

1.4 A Macro for Simplifying Input .......................................................... 15

1.5 A Simple Literature Database ............................................................ 17 1. 6 A Form for Computing Interest in a Savings Account ............. 24 1. 7 User-Defined Functions .......................................................................... 30

1.8 Analysis of Complex Tables ................................................................. 31

1. 9 A Vocabulary Tutor .................................................................................. 32 1.10 Example Programs for You to Try .................................................... 40

Chapter 2 What~s New in Excel 2000 ....................................... .47

2.1 New in Excel 2002 ..................................................................................... 48

2. 2 New in Excel 2000 .................................................................... " ............... 51 2.3 New in Excel 97 ........................................................................................ ,54 2. 4 New in Excel 7 .......................................................................................... ,59

2. 5 Problems and Incompatibilities ........................................................ 59

V

Contents

Part Two Fundamentals ............................................................................................. 65

Chapter 3 The Development Environment ................................. 67

Chapter Overview ................................................................................................ 67 3.1 The Components of a VBA Program ...................................................... 68 3. 2 The Components of the Development Environment ....................... 69

Object Browser ................................................................................................. 72 3. 3 Code Input in Modules ............................................................................ 76 3.4 Executing Macros ....................................................................................... 80 3. 5 Recording Macros ....................................................................................... 82 3. 6 Keyboard Shortcuts .................................................................................. 83

Chapter 4 VBA Concepts ........................................................................ 85

4.1 Variables and Fields .............................................................................. 86 ManagingVariables .......................................................................................... 86 Syntax Summary ............................................................................................... 95

4.2 Procedural Programming .......................................................................... 97 Procedures and Parameters ............................................................................. 97 Realm ofValidity ofVariables and Procedures ............................................. 107 Branching (Tests) ........................................................................................... 112 Loops ............................................................................................................... 115 Syntax Summary ............................................................................................. 119

4.3 Objects ......................................................................................................... 123 Workingwith Objects, Methods, and Properties ......................................... 123 The Object Browser (References) .................................................................. 129 Accessing Objects Clarified with Keyword With .......................................... 134 ObjectVariables .............................................................................................. 135 Syntax Summary ............................................................................................. 138

4.4 Events ........................................................................................................... 139 Event Procedures ............................................................................................ 140 Overview of Important Excel Events ............................................................. 144 Receiving Events of Arbitrary Objects ........................................................... 150 Generating Event Procedures with Program Code ...................................... 152 Syntax Summary ............................................................................................. 156

4.5 Programming Your Own Classes ........................................................... 159 Custom Methods, Properties, and Events .................................................... 161 Collection Object ............................................................................................ 165 Example for a Class Module .......................................................................... 167

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Contents

Example for Derived Classes (Implements) ................................................. 168

Syntax Summary .............................................................................. ............... 173

4.6 Operators in VBA ..................................................................................... 175

4. 7 Virus Protection ..................................................................................... 178

Chapter 5 Techniques of Programming ..................................... 185

5.1 Cells and Ranges of Cells ................................................................. 186

Objects, Methods, Properties ........................................................................ 186

ProgrammingTechniques .............................................................................. 201

Syntax Summary ............................................................................. ................ 212

5. 2 Workbooks, Windows, and Worksheets .............................................. 215

Objects, Methods, and Properties ................................................................. 215

Programming Techniques .......................................................... .................... 221

Syntax Summary .......................................................................................... ... 226

5. 3 Data Transfer via the Clipboard .................................................... 228

Copying, Cutting, and Pasting Ranges of Cells ......................................... ... 228

Access to the Clipboard with the DataObject .............................................. 230

Syntax Summary .......................................................................................... ... 231

5.4 Warking with Numbers and Character Strings ............................ 232

Numerical Functions, Random Numbers ............................................ ........ 232

Character Strings ........................................................................................... . 235

Transformation Functions ............................................................................. 241

Syntax Summary .......................................................................................... ... 243

5.5 Warking with Dates and Times ........................................................... 246

VBA Functions ...................................................................................... .......... 250

Worksheet Functions ..................................................................... ................ 253

Application and Programming Techniques ................................................ . 254

Holidays .................................................................................................... ...... 257

Syntax Summary ............................................................................... .............. 265

5.6 Warking with Files; Text Import and Export ............................ 267 File System Objects: An Overview ................................................................. 267

Drives, Polders, and Files .............................................................................. . 269

Text Files (TextStream) ........................................................................... ........ 276

Binary Files (Open) ......................................................................................... 278

Excel-Specific Methods and Properties ........................................................ 283

Importing and Exporting Text Files ................................................... .......... .286

Text Exportation for Mathematica Lists ..................................................... .. 296

Syntax Summary ............................................................................................. 301

5. 7 User-Defined Worksheet Functions .................................................. 306

Fundamentals ................................................................................................. 306 Examples ......................................................................................................... 314

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Contents

5. 8 Protection Mechanisms .......................................................................... 317 Restricting the Field of Action ....................................................................... 318 Protecting Cells and Worksheets from Changes .......................................... 319 Protection Mechanism for Shared Workbooks ............................................ 324 Protecting Program Code and ToolBars .............................................. ......... 324 Syntax Summary ......................................................................................... .... 326

5.9 Configuration Files, Custom Configuration .............................. 327 Options ..................................................................................................... ....... 327 Setting Options with Program Code ............................................................ . 328 Configuration Files ....................................................................................... .. 332

5.10 Excel Meets the Euro .......................................................................... 339 The Euroconvert Function ...................................................................... ...... 340 Converting Excel Files to the Euro ................................................................ 343

5.11 Tips and Tricks ..................................................................................... 356 Speed Optimization ....................................................................................... 356 Time-Intensive Calculations ...................................................................... ... 357 Warking Efficiently with Worksheets ............................... ............................. 362 Interplay with Excel-4 Macras ....................................................................... 365 Determining the Version of Excel ................................................................ .. 366 HelpingYou to Help Yourself ......................................................................... 366 Syntax Summary ........................................................................................... .. 368

Chapter 6 Debugging~ Protection When Errors Arise .. 371

Chapter Overview .............................................................................................. 371 6.1 Debugging Aids ......................................................................................... 372

Syntax Control ................................................................................................ 372 Reaction to Errors ........................................................................................... 373 Contralied Program Execution ...................................................................... 376

6.2 Error- Tolerant Behavior of Programs ........................................... 380 6.3 Response to Program Interrupts ...................................................... 385 6. 4 Syntax Summary ......................................................................................... 386

Chapter 7 Forms (Microsoft Forms Library) ..................... 387

7.1 Predefined Dialogs ................................................................................ 388 Standard Excel Dialogs ................................................................................... 388 The Functions MsgBox and InputBox ........................................................ .. 392 The Method Application.InputBox ............................................................. .. 393

7. 2 User-Defined Forms ................................................................................ 395 Changes with Respect to ExcelS/7 ............................................................... 396 Introductory Example ....................................................................... ............. 398

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Contents

7.3 The Form Editor ....................................................................................... 402 7. 4 The MS Forms Controls .......................................................................... 406

Label ................................................................................................................ 408 TextBox ............................................................................................................ 409 ListBox and ComboBox .................................................................................. 412 Check Box and OptionButton ....................................................................... 419 Command Buttons and Toggle Buttons ...................................................... .421

Frames ............................................................................................................. 422 MultiPage, TabStrip ........................................................................................ 424 Scrollbar and SpinButton .............................................................................. 429 Image ............................................................................................................... 431 Formulas (RefEdit) ......................................................................................... 432 The UserForm Object ..................................................................................... 434

7.5 Placing Controls Directly into Worksheets ............................. .438

7. 6 Programming Techniques ....................................................................... .447 Numerical Input ............................................................................................. 447 Reciprocal Calling ofForms ........................................................................... 449 Editing Forms Dynamically ........................................................................... 451 Working with Spin Buttons ............................................................................ 453

Chapter 8 Menus and Toolbars ...................................................... .457

8.1 Menu Bars and Toolbars ........................................................................ 458 Manual Editing of Menus and Toolbars ....................................................... .458 Saving Changes ............................................................................................... 464 Object Hierarchy ............................................................................................ 466 ProgrammingTechniques .............................................................................. 472 Changing Sheets via a Toolbar ...................................................................... 479 Differences Compared to Excel5/7 ............................................................. .482 Syntax Summary ............................................................................................. 483

8.2 Formatting the Interface for Freestanding Excel Applications ......................................................................................... 485

Extending the Standard Menu ....................................................................... 486 Hiding and Unhiding Custom Toolbars ....................................................... .489

Using a Custom Standard Menu ................................................................... 490

ix

Contents

Part III Application .............................................................................................. 493

Chapter 9 Templates, Smart Forms .......................................... .495

9.1 Fundamentals .............................................................................................. 496 Design Elements for Smart Forms ................................................................ 497 Templates Linked to Databases ................................... ................................. 505

9. 2 Example: The ((SpeedyJJ Invoice Form .............................................. 509

9.3 Example: Balance Sheet for a Car-Sharing Club ..................... 518

9.4 The Limits of Smart Forms ................................................................. 525

Chapter 10 Charts and Drawing Objects (Shapes) ........... 527

10.1 Charts ......................................................................................................... 528 Fundamentals ................................................................................................. 528 Chart Types ..................................................................................................... 529 Chart Elements (Chart Objects) and Formatting Options .......................... 530

Printing ............................................................................................................ 534 10.2 Programming Charts .............................................................................. 535

Object Hierarchy ............................................................................................ 536 ProgrammingTechniques .............................................................................. 540

10.3 Example: Automatie Data Reporting .............................................. 544

Using the Example Program ......................................................................... . 544

Program Code ................................................................................................. 547 10.4 Syntax Summary for Charts ............................................................... 558 10.5 Drawing Objects (Shapes) ................................................................. 560 10.6 Diagrams .................................................................................................... 565

Chapter 11 Data Management in Excel ....................................... 569

11.1 Fundamentals ........................................................................................... 570

Introduction: What Is a Database? ................................................................ 570 ABrief Database Glossary .............................................................................. 571 Excel Versus Database Systems ................................................................. .... 572

11.2 Data Management Within Excel ........................................................ 575 Creating a Database in Excel ......................................................................... 576 Input, Alteration, and Deletion of Data with the Database Form .............. 579

Sorting, Searching, and Filtering Data .............................. ............................ 581

11.3 Data Processing in VBA Code ........................................................... 588 Programming Techniques .............................................................................. 588

X

Contents

Example: A Form Letter in Microsoft Word .................................................. 591

Syntax Summary ............................................................................................. 594

11.4 Database Worksheet Functions ........................................................ 595

11.5 Consolidating Tables .......................................................................... 599

Fundamentals ................................................................................................. 599

Consolidation via VBA Code .......................................................................... 601

11.6 Example: Balance Sheet for a Car-Sharing Club ................... 602

Running the Program ..................................................................................... 603

Overview of the Components of the Application ........................................ 607

Program Code ................................................................................................. 608

Chapter 12 Access to External Data .......................................... 619

12.1 Fundamental Concepts About Relational Databases ............... 620

12.2 Importing External Data ................................................................... 626

Importing Data from Databases (MS Query) ............................................... 627

The QueryTable Object .................................................................................. 639

Exporting Excel Data ...................................................................................... 643

12.3 Database Access with the ADO Library ....................................... 645

Introduction .................................................................................................... 645

Connections .................................................................................................... 650

Recordset ......................................................................................................... 654

SQL Commands (Command) ........................................................................ 662 SQL Basics ....................................................................................................... 663

Syntax Summary ............................................................................................. 666

12.4 Example: Evaluating a Questionnaire ......................................... 669 Overview ......................................................................................................... 669

Construction ofthe Database ....................................................................... 674 Program Code ................................................................................................. 675

Chapter 13 Data Analysis in Excel ............................................ 687

13.1 Grouping Data (Subtotals) ............................................................... 688

Introducdon .................................................................................................... 688

Programming .................................................................................................. 689

13.2 Pivot Tables ........................................................................................... 692

Introduction .................................................................................................... 692

Layout Options ............................................................................................... 697

Pivot Tables for External Data ....................................................................... 703

Pivot Table Options ........................................................................................ 708

Pivot Charts ..................................................................................................... 709

xi

Contents

13.3 Programming Techniques ...................................................................... 710 Generating and Deleting Pivot Tables .......................................................... 711

Construction and Reconstruction of Existing Pivot Tables ......................... 716 Internal Management (PivotCache) ............................................................. 720

Syntax Summary ............................................................................................. 728

Chapter 14 VBA Programming for Pros ....................................... 731

14.1 Add-Ins ....................................................................................................... 732

14.2 Excel and the Internet ...................................................................... 737

Sending Excel Files as E-Mail ........................................................................ 737

HTML Import ................................................................................................. 739

HTML Export, Web Components .................................................................. 740

14.3 Smart Tags ................................................................................................ 744

14.4 Using Web Services .............................................................................. 747

14.5 Using Dynamic Link Libraries (DLLs) ......................................... 754

14.6 ActiveX Automation ............................................................................. 759

Excel as Client (Controlling External Programs) .......................................... 761

Excel as Server (Control by an External Pro gram) ....................................... 767 New Objects for Excel ( ClipBoard Example) ................................................ 772 Object Linking and Embedding (OLE) ......................................................... 775

Automation and Visual Basic .NET ............................................................... 780 Launehing and Controlling Programs Without ActiveX .............................. 786 Syntax Summary ............................................................................................. 789

Part Four Reference ..................................................................................................... 791

Chapter 15 Object Reference ............................................................ 793

15.1 Object Hierarchy ................................................................................... 794

15. 2 Alphabetical Reference ...................................................................... 801

Appendix Excel 2003 Beta 2 ......................................................... 863

References ........................................................................................................ 879

Index .................................................................................................................... 881

xii

Preface

ExCEL OPFERS RIGHT OUT OF THE BOX an enormaus variety of functions. So why does

one need VBA macros? With VBA you can accomplish wonders:

• You can program your own worksheet functions that are easier to use than complicated formulas.

• You can configure Excel to suit your requirements and in this way achieve greater simplicity and efficiency.

• You can structure and simplify complex processes such as filling out forms by means of"smart" forms (templates).

• You can automate processes that are used frequently. This is particularly useful in dealing repeatedly with large data sets that must be processed, analyzed, and graphically displayed.

• You can create freestanding Excel programs that display their own menus, dialogs, and toolbars. This makes it possible to simplify an Excel application to the point where those unfamiliar with Excel can run the program correctly.

What's New in Excel 2000 and 2002?

With Excel97, the VBA programming modeland the most important object libraries became fairly stable. Excel 2000 and 2002 introduced a hast of new

objects, but in practice these are seldom used (if for no other reason than to make

VBA applications backward compatible with the widely distributed Excel97). The

most important innovations are the Scripting and ADO libraries, both of which have been available since Excel2000, simplifying access to files, directories, and

extemal databases.

Excel and .NET

In connection with Microsoft's .NET offensive, it should be mentioned that Office

2000 and 2002 are not yet .NET compatible. Even the forthcoming Office edition

scheduled for release sametime in 2003 will not be based on .NET, according to

current ward from Microsoft. But that is no reason for tears. If Microsoft were

xiii

Preface

xiv

someday to decide actually to convert the Officesuite to .NET and the new pro­

gramming language VB.NET, then there would be a great number of compatibility

problems built into Excel. An important function of .NET, namely, the so-called web services, can

already be used with Excel2000 and 2002 without compatibility problems. The

Web Services Toolkit, a simple and freely distributed extension of the VBA devel­

opment environment, makes this possible. (Details on the use of this toolkit

appear in Chapter 14.)

Why This Book?

The real problern in VBA programming is not VBA itself. The formulation of a loop

ortest, the use of methods and properties, are easily understood as in any pro­

gramming language and will cause you no trouble after a couple of days. The

problern is to get a handle on the complex object libraries within Excel, with their

more than a thousand keywords, and to use them efficiently. The focus of this

book and the examples presented herein is to explain these object libraries.

In cantrast to Excel's Help, the goal of this book is not to offer merely a refer­

ence-often one that says next to nothing-of key words. It is our purpose to show

the connections among the numerous objects and to demonstrate their use with

concrete application examples as they appear in the real world. We do not hesitate to pointout problems with Excel where they exist, in order to spare you, the

reader, from a fruitless search for errors ofwhich you were not the cause.

Enjoy!

The examples of this book show just how far one can go with Excel programming.

The possibilities are truly endless. This book will help you to become acquainted

quickly with Excel's object model, and once you have gatten over that hurdle

(figure one or two weeks), you will find that VBA programming is a lot of fun.

Therefore, I wish you great success and plenty of fun and enjoyment in your

Excel programming. Michael Kofler, May 2003

http://www.kofler.cc

The Idea Behind This Book

VrsuAL BASIC FOR APPUCATIONS is, to be sure, a modern object -oriented programming language that offers an incredible number ofkeywords, but at the sametime it offers many difficulties. At the beginning one has no hope of gaining even an overview ofVBA. And even after months of programming in VBA the on -line help will remain the most important source of advice on the details of a particular key­word. Therefore, this book attempts to compensate for the shortcomings in the original documentation and the on -line help by providing the following assistance:

• Genuine applications in the form of concrete, realistic examples

• Thematic syntax summaries (for example, a11 properties and methods for dealing with ranges of cells)

• Detailed information on the use of DLL functions, on ActiveX automation, on the creation of custom on-line help texts, on programming your own add-ins.

• Useful descriptions of all VBA objects and their arrangement in the object hierarchy

• Information on inconsistiencies and errors in VBA

However, there is one attribute that this book does not possess: completeness. There is no point, it seems to me, in filling hundreds of pages with a reference to a11 keywords when practically the same information can be found in the on-line help. Instead of seeking to give only the appearance of completeness, I have attempted to give preference to the most important topics and to deal with these

in full detail.

Formalities

Keyboardshortcuts are given in the form Ctri+F2. Menu commands appear as fol­lows: FrLEIÜPEN, CA.NcEL, or OK. The instruction EorriDELETEISHIFI' cells left means that you first execute the menu command EorriDELETE and then in the dialogthat appears select the button Shift cells left.

XV

The Idea Behind This Book

xvi

VBA keywords as weil as variables and procedures are written in italics, for

example, "Application object" or "Visible property." Worksheet functions are writ­

ten in the same type style, but in all uppercase letters, as in IF, for example.

(In international versions of Excel it is necessary to distinguish worksheet

functions from VBA keywords: VBA keywords are always in English, while work­

sheet functions must be given in the locallanguage.) Keywords that appear in the

text for the firsttime with an explanation orthat are particularly important are

printed in hold italics.

The Example Files

The example flies for this book are available at http: I lwww. Apress. com in the

downloads section.

Excel XP or Excel 2002? Office XP or Office 2002?

Microsoft markets the current version of its Office suite as Office XP, though

the version of Excel contained in Office XP is usually referred to as Excel2002.

In any case, they are the same. Excel2002 = Excel XP. This book uses the names

Excel2002 and Office 2002.