UPGRADING MICROSOFT VISUAL BASIC 6.0 TO MICROSOFT VISUAL BASIC .NET（影印版）

PART I INTRODUCTION TO UPGRADING

1 Visual Basic .NET Is More Than Visual Basic 6 + 1 3

Why Break Compatibility? 6

Adding New Features 6

Fixing the Language 7

Modernizing the Language 8

It Is Still Visual Basic 8

Expect Subtle Differences 8

Plan for a 95 Percent Automated Upgrade 9

Why Should I Upgrade? 10

New Language Features 10

Windows Forms 14

New Web Development Features 15

Better Development Environment 15

Is Visual Basic Still the Best Choice for Visual Basic Developers? 16

Conclusion 18

2 Visual Basic 6 and Visual Basic .Net: Differences 19

.NET Framework vs. ActiveX 19

.NET Framework 21

Memory Management 22

Type Identity 25

Threading Model 29

Differences in the Development Environment 29

Menu Editor 30

Toolbox 31

Property Browser 32

Tab Layout Editor 33

Forms Packages 34

A Single Standard for Windows Forms 34

Two Forms Packages for the Price of One 35

Language Differences 35

All Subroutine Calls Must Have Parentheses 37

ByVal or ByRef Is Required 38

Is That My Event? 38

Arrays Must Have a Zero-Bound Lower Dimension 39

Fixed-Length Strings Are Not Supported 40

Variant Data Type Is Eliminated 40

Visibility of Variables Declared in Nested Scopes Is Limited 41

Changes in the Debugger 42

No Edit and Continue 42

Cannot Continue After an Error 42

No Repainting in Break Mode 42

Conclusion 43

3 Upgrading Options 45

Upgrading Is Optional 45

Don’t Upgrade 45

Partial Upgrade 46

Complete Upgrade 47

Upgrade with Interoperability 47

Role of the Upgrade Wizard 48

The Upgrade Report 48

Testing 49

Upgrading from Earlier Versions of Visual Basic 49

Selecting Projects to Upgrade 50

Evaluating the Benefits 51

Evaluating the Effort Required 55

Developing the Upgrade Plan 58

Conclusion 59

4 Preparing Your Project for the Upgrade to Visual Basic .NET 61

Why Change Anything? 61

Cleaning Up Legacy Code 62

VarPtr, DefInt, and Other No-Shows 62

DAO and RDO Data Binding 63

Good Visual Basic 6 Coding Practices 64

Variants and Variables 64

Abstraction 66

Early Binding vs. Late Binding vs. Soft Binding 69

Watch Out for Null and Empty 73

Implicit Object Instantiation 74

Conclusion 76

PART II UPGRADING APPLICATIONS

5 Your First Upgrade 79

Upgrade Walkthrough 79

What Just Happened? 85

Language Changes 88

Other Files in Your Project 92

Upgrading Project Groups 94

Using the VB Snippet Upgrade Add-In 98

Upgrading Using the Command Line 99

Conclusion 100

6 Common Tasks in Visual Basic .NET 101

A Guide to Working in Visual Basic .NET 101

Creating a Visual Basic .NET Project 102

Getting to Know the Visual Studio .NET IDE 104

Running Your Project 106

A Quick Introduction to Debugging 107

Miscellaneous Items 108

Handling Build Errors 108

Using the Task List 109

Using Breakpoints 110

References 111

Problem-Solving Techniques 112

Using the System.Diagnostics Library 112

Using CorDbg 113

Simplifying Complex Expressions 114

Conclusion 115

7 Upgrade Wizard Ins and Outs 117

Upgrade Philosophy 117

It’s Your Code 117

Just Make It Work 118

Compatibility Library 119

Upgrade Wizard Capabilities and Limitations 119

Wizard Methodology 119

Project Upgrade 121

Forms and Intrinsic Controls 128

ActiveX Controls and ActiveX References 137

Visual Basic Code 140

Global Objects 145

Class Modules and User Controls 145

Objects for Accessing Data 146

Designers 147

Conclusion 148

8 Errors, Warnings, and Issues 149

The Different Kinds of EWIs 152

Upgrade Issues 152

Upgrade ToDos 153

Run-Time Warnings 154

Design Issues 154

Upgrade Notes and Global Warnings 155

Understanding the Upgrade Report 155

Estimating Fix Time 157

Working with EWIs 159

The Different Upgrade EWIs 160

Upgrade Issues 160

Upgrade ToDos 163

Upgrade Warnings 164

Design Errors 167

Global Warnings 169

Upgrade Notes 170

Which Problems Are Not Detected? 172

Conclusion 174

9 Using Visual Basic 6 with Visual Basic .NET: COM Interop 175

Where COM Interop Comes into Play 177

ActiveX Controls 177

Communication Between a .NET Client and a COM Server Component 177

Communication Between a COM Client and a .NET Server Component 178

Upgrading a Visual Basic 6 Client/Server Application 178

Creating a .NET Client That Talks to a COM Server 180

Debugging Between the Visual Basic .NET Client and Visual Basic 6 Server 182

Exposing a Visual Basic .NET Component to Be Called by a Visual Basic 6 Client 184

Debugging Between the Visual Basic 6 Client and .NET Server 187

Tying It All Together 188

Replacing COM with .NET: Binary Compatibility 189

Indirect Replacement Model 190

Enabling Binary Compatibility in Visual Basic .NET Classes 191

Conclusion 196

PART III GETTING YOUR PROJECT WORKING

10 Ten Common Upgrade Problems 199

Default Properties 199

AddItem and ToString with COM Objects 201

Deterministic Finalization and Garbage Collection 203

Bringing a Little Determinism to the Party 205

Generic Objects (Control/Form/Screen) 206

Dim…As New 207

Sub Main (or Default Form) 208

Font Disparities 209

Bad Constants 212

Drag and Drop 213

Drag and Drop in Visual Basic 6 213

Drag and Drop in Visual Basic .NET 215

Collection Classes 219

Conclusion 222

11 Resolving Issues with Language 223

Language Elements 224

#If…#End If Precompiler Statements 224

Constants and Constant Expressions 224

Control Flow 227

File Functions 232

Types and Type Operations 238

Object Replaces Variant 238

Arrays 242

Structures 245

Making Your Code Thread-Safe 249

Windows API 251

Type Changes 252

As Any No Longer Supported 253

AddressOf Changes 254

Passing User-Defined Types to API Functions 258

ObjPtr and StrPtr Not Supported 261

Conclusion 263

12 Resolving Issues with Forms 265

Similarities in Form Structure 265

General Issues 267

Differences in Properties, Methods, and Events 267

Technology Differences 269

Issues Involving Forms 274

Event Firing Differences 274

The Default Form: DefInstance 277

Application Lifetime and Forms 278

MDI Forms 282

Conclusion 283

13 Upgrading ActiveX Controls and Components 285

ActiveX Controls Are Still Supported—Yes! 285

ActiveX Upgrade Strategy 286

Limitations of ActiveX Control Hosting 286

ActiveX .NET Controls: Best of Both Worlds 289

ActiveX Interop Ax Wrapper: The Windows Forms Wrapper 289

Property and Parameter Type Mappings 290

Standard Component Wrappers and ActiveX Control Subobjects 293

Common Exceptions That Require Type Conversions 295

Name Collisions 297

Event Name Collisions 297

Using ActiveX Components from .NET 298

When ByRef Bites 298

When a Collection Is Not a Collection 299

Nonzero-Bound Arrays 301

Alias Types Are Not Supported 301

Module Methods Are Not Supported 302

Conclusion 303

14 Resolving Data Access Issues 305

Data Access in Visual Basic 306

Code 306

Data Binding 307

ADO Data Environment 307

Components That Don’t Upgrade 308

ADO.NET Is the Future 309

General Issues with Data Access Code 309

DAO and RDO Module Methods 309

ADO Version 2.7 311

Errors in Events 311

RDO Connection 313

Null, vbNullString, and vbNullChar 314

ADO Data Environment 315

Calling Dispose 315

Initialize Event 316

Cursor Location with Microsoft Access Databases 316

ADO Data Binding 316

Control Arrays of ADO Data Controls 318

Setting Data Binding Properties at Run Time 318

Conclusion 321

15 Problems That Require Redesign 323

Replacing the OLE Container Control 323

Replacing Painting Functions 328

Rewriting Clipboard Code 331

Using the Controls Collection 333

Using the Forms Collection 335

Upgrading PrintForm Code 337

Replacing Property Pages 340

Eliminating ObjPtr, VarPtr, and StrPtr 343

Conclusion 345

16 Upgrading COM+ Components 347

COM+ Application Types 347

Using COM+ in Visual Basic .NET 348

COM+ Requirements in Visual Basic .NET 350

Inheriting from the ServicedComponent Class 351

Working with Attributes 352

Creating a Strong Name for Your Assembly 356

Registering COM+ Applications 358

Upgrading COM+ Components 360

Making .NET and COM Components Work Together 364

Conclusion 364

17 Upgrading VB Application Wizard Projects 365

App.Revision 367

frmAbout Form 369

frmLogin Form 370

frmMain Form 370

API Declare Statements 370

mnuHelpAbout_Click Event Procedure 371

App.HelpFile 371

ActiveMdiChild in MDI Projects 372

Forms Collection in frmMain_Closed 374

Clipboard in MDI Projects 375

frmSplash Form 376

frmBrowser Form 378

Data Forms 378

Module1 Module 379

LoadResStrings Method 379

Conclusion 381

PART IV TECHNIQUES FOR ADDING VALUE

18 Adding Value to Your Applications 385

Overview of the Sample Application 386

New File Functions 387

Reading the Contents of a Directory 387

Finding All the Forms in a DLL 388

Loading Forms Dynamically 389

Reading and Writing to Files 389

Using Dynamic Properties 390

New Windows Capabilities 392

Accessing the Registry 392

Control Anchoring 394

Graphics Features 394

Windows XP–Style Controls 398

XCopy Deployment 400

Conclusion 401

19 Replacing ActiveX Controls with Windows Forms Controls 403

Benefits of Upgrading Controls 404

100 Percent .NET Compatibility 404

Improved Versioning 404

Simpler Deployment 405

Process of Replacing Controls 405

Manually Upgrading a Control 406

Mappings for Visual Basic 6 ActiveX Controls 412

ActiveX Controls vs. Windows Forms Controls 413

Conclusion 416

20 Moving from ADO to ADO.NET 417

ADO.NET for the ADO Programmer 417

Overview of ADO.NET 418

DataSets 419

Integrating Your ADO Code into a Visual Basic .NET Application 421

Binding Your ADO Recordset to .NET Controls 422

Using ADO with XML Web Services 423

Mapping ADO Objects to ADO.NET 425

Connection and Command Objects 425

Recordsets 427

Using DataViews 429

Data Binding 430

Binding to Windows Forms Controls 430

A Note About Performance 432

Conclusion 434

21 Upgrading Distributed Applications 435

Important Concepts for Distributed Applications 436

Loosely Coupled vs. Tightly Coupled Applications 436

Overhead in Method Invocation 437

Componentization and Logical Organization 439

Distributed Technologies in .NET 440

XML Web Services 440

Creating a Simple XML Web Service 441

Supporting Web Services in Your Existing Applications 446

Remoting 452

A Simple Remoting Example 453

Architecture for Remoting 456

Distributed COM+ Applications 461

COM+ and Remoting 461

Using SOAP Services 461

COM+ Application Proxies in .NET 463

Conclusion 464

PART V APPENDIXES

APPENDIX A Object Mapping Reference 467

APPENDIX B Function Mapping Reference 515

INDEX