Visual Basic Developer's Guide to Com and Com+

by Freeze, Wayne S.; Sybex Inc.

• ISBN13: 9780782125580
• ISBN10: 0782125581
• Edition: 4th
• Format: Paperback
• Copyright: 1999-10-01
• Publisher: John Wiley & Sons Inc

Summary

Freeze offers coverage of the new COM standard, COM+, which will be an integral part of Windows 2000. He includes full coverage of working with MTS (Microsoft Transaction Server) and MSMQ (Microsoft Message Queue), both underpublished topics.

Table of Contents

Foreword	p. xxii
Introduction	p. xxiii
Understanding COM	p. 1
Introducing COM	p. 3
What Is COM?	p. 4
What Is a Component?	p. 4
What Is an Object?	p. 6
What Is the Component Object Model?	p. 7
Why Is COM Important to You?	p. 8
From DDE to COM+	p. 9
DDE	p. 9
OLE 1	p. 10
Basic Becomes Visual	p. 11
VBX	p. 12
OLE 2 and COM	p. 14
ActiveX	p. 15
COM and DCOM	p. 16
Transactions and Queues	p. 17
COM+	p. 19
Final Thoughts	p. 20
Understanding Windows Architecture	p. 23
Types of Program Files	p. 24
COM Files	p. 24
EXE Files	p. 25
DLL Files	p. 25
Other Types of Files	p. 26
Program Execution	p. 26
Locating and Loading the Program	p. 26
Locating and Loading Runtime Libraries	p. 27
Resolving Conflicts	p. 28
Initializing Files	p. 28
Ending the Program	p. 28
Virtual Memory	p. 29
Using Virtual Memory	p. 29
Allocating Memory	p. 32
Program Execution Control	p. 34
Processes and Threads	p. 35
Multithreading	p. 35
Marshaling	p. 36
Final Thoughts	p. 37
Running COM Objects	p. 39
The Life of an Object	p. 40
Creating an Object	p. 40
Using an Object	p. 41
Deleting an Object	p. 42
What's Inside a COM Object?	p. 44
Interfaces	p. 45
Using Standard Interfaces	p. 45
Using Custom Interfaces	p. 47
Accessing Information through an Interface	p. 48
Binding to an Interface	p. 48
In-Process COM Objects	p. 49
Finding and Loading In-Process COM Objects	p. 49
Understanding In-Process Threading Models	p. 51
Out-of-Process COM Objects	p. 53
Finding and Loading Out-of-Process COM Objects	p. 54
Understanding Out-of-Process Threading Models	p. 55
Running Out-of-Process COM Objects Remotely	p. 56
DCOM Objects	p. 57
Finding DCOM Objects	p. 57
Running DCOM Objects	p. 57
COM+ Objects	p. 58
Final Thoughts	p. 58
Building Class Modules in Visual Basic	p. 61
Programming with Class	p. 62
Elements of the Class Module	p. 63
The Class Name	p. 64
Initialization and Termination Routines	p. 64
The Public, Private, and Friend Keywords	p. 64
Module Variables	p. 65
Public versus Private Variables	p. 65
Module Variable Declaration Syntax	p. 66
Property Routines	p. 67
Property Get Syntax	p. 68
Property Let and Property Set Syntax	p. 69
Method Routines	p. 70
Event Declarations	p. 72
Event Declaration Syntax	p. 72
RaiseEvent Syntax	p. 73
A Classy Little Application	p. 73
Setting Up the Stack Interface	p. 74
Using the Object Browser	p. 75
Building the Stack Class	p. 77
Using the Stack Class	p. 81
Final Thoughts	p. 83
Programming COM with Visual Basic	p. 85
Creating ActiveX DLL Objects in Visual Basic	p. 87
What Is an ActiveX DLL?	p. 88
Why Use an ActiveX DLL?	p. 89
Building an ActiveX DLL	p. 90
Setting the Project's Properties	p. 91
Setting Class Module Properties	p. 97
Creating the TimeInfo Class	p. 99
Creating the RunMe Class	p. 105
Testing the ActiveX DLL	p. 110
Adding Another Project	p. 110
Building the Test Program	p. 111
Using the ActiveX DLL	p. 115
Compiling the ActiveX DLL	p. 115
Registering Your ActiveX DLL	p. 116
Adding Your ActiveX DLL to a New Program	p. 117
Final Thoughts	p. 118
Creating ActiveX Controls	p. 121
What Makes an ActiveX Control Different?	p. 122
ActiveX Control Project Properties	p. 122
License Keys	p. 123
The UserControl Object	p. 124
Containers, Constituents, and Other Stuff	p. 125
UserControl Properties, Methods, and Events	p. 125
Building a Simple ActiveX Control	p. 131
Designing the PicView Control	p. 131
Drawing the PicView Control	p. 133
Coding the PicView Control	p. 134
Adding Information about Your Properties, Methods, and Events	p. 141
Creating Property Pages	p. 142
Using Standard Property Pages	p. 143
Designing a Property Page	p. 145
Understanding Property Page Properties and Events	p. 146
Adding an About Box	p. 150
Creating the About Box	p. 150
Hooking the Window to the Control	p. 152
Final Thoughts	p. 153
Creating ActiveX EXE Objects	p. 155
What Makes an ActiveX EXE Different?	p. 156
Programming with More Class	p. 157
Object Creation and Access	p. 157
Threading Models	p. 160
An ActiveX EXE Can Have Forms, Too	p. 162
Building an ActiveX EXE	p. 162
How the EchoClient Program Works	p. 162
The EchoServer Object	p. 164
Missing Object Files	p. 165
The EchoText Method	p. 166
Asynchronous Processing	p. 167
Design Overview	p. 167
Starting in the Client	p. 168
Then onto the Server	p. 168
To Start the Task	p. 169
When the Timer Fires	p. 169
The AsyncTask Will Run	p. 171
And Return via the EchoMessage Event	p. 171
While I Was Waiting	p. 172
Designing Multipurpose Programs	p. 173
Start Mode	p. 173
Sub Main and the About Box	p. 174
Sub Main and a Real Application	p. 175
Finishing Your ActiveX EXE Server	p. 175
Compiling Your Server	p. 176
Installing Your Server	p. 176
Accessing Remote Objects	p. 177
Final Thoughts	p. 178
Moving from COM to DCOM	p. 181
How Is DCOM Different?	p. 182
DCOM Configuration	p. 182
Design Considerations for DCOM Objects	p. 183
Running the DCOM Configuration Utility	p. 184
Setting Windows 2000/NT Options	p. 184
Setting Windows 95/98 Options	p. 198
EchoServer and EchoClient Revisited	p. 205
Troubleshooting Common DCOM Errors	p. 208
Error 70: Permission Denied	p. 208
Error 429: ActiveX Component Can't Create Object	p. 209
Error 462: The Remote Server Machine Does Not Exist or Is Unavailable	p. 210
Final Thoughts	p. 210
Programming Databases with COM Objects	p. 213
Using Data Sources and Consumers	p. 214
Data Sources	p. 215
Data Consumers	p. 215
Building Bound Controls	p. 217
Database Design	p. 218
The DataSpinner Control	p. 218
The AddressDisplay Control	p. 224
The AddressBook Program	p. 228
Final Thoughts	p. 230
Programming COM+ with Visual Basic	p. 233
Introducing COM+	p. 235
Transaction Processing	p. 236
Atomicity	p. 237
Consistency	p. 237
Isolation	p. 238
Durability	p. 238
Message Queues	p. 238
The In-Memory Database System	p. 239
Other COM+ Features	p. 240
COM+ and Visual Basic	p. 241
COM+ Applications	p. 242
Transaction Types	p. 243
Transaction Context	p. 244
A Simple COM+ Application	p. 247
The Database Tables	p. 248
The COM+ Application's Properties	p. 250
The COM+ Component's Properties	p. 255
COM+ Object Construction	p. 259
COM+ Component Definition	p. 262
Client Program Construction	p. 267
Final Thoughts	p. 268
Understanding Message Queues	p. 271
Understanding How Message Queues Work	p. 272
Synchronous versus Asynchronous Processing	p. 272
Result Return	p. 274
Types of Queues	p. 274
Benefits of Message Queues	p. 275
Using Message Queues from Visual Basic	p. 277
Public and Private Queues	p. 277
Message Queue Objects	p. 278
Message Queues and COM+ Transactions	p. 288
Building COM+ Message Queues	p. 290
Design Approach	p. 290
Request Processing	p. 292
Introducing Queued Components	p. 296
How Queued Components Work	p. 296
Limitations of Queued Components	p. 297
Final Thoughts	p. 297
Understanding the In-Memory Database System	p. 301
Understanding How IMDB Works	p. 302
Deciding If IMDB Is for You	p. 303
Volume of Data	p. 303
Static versus Dynamic Loading	p. 304
The Read-to-Write Ratio	p. 304
The Total I/O Rate	p. 305
Shared Data	p. 305
Preparing to Use IMDB	p. 305
IMDB Configuration	p. 306
IMDB Security Settings	p. 307
Using IMDB in an Application	p. 312
Programming Considerations	p. 313
A New Collection Object	p. 314
ContactManager Object Enhancements	p. 316
The User Program	p. 320
Final Thoughts	p. 322
Understanding Security in COM+	p. 325
Types of Security under COM+	p. 326
Authentication	p. 326
Impersonation and Delegation	p. 327
Role-Based Security	p. 328
Configuring Security	p. 328
Planning Security	p. 328
Defining Security Roles	p. 330
Adding Users to a Role	p. 332
Associating Roles with Components	p. 332
Associating Roles with Interfaces	p. 333
Enabling Security on an Application	p. 335
Programming Security	p. 336
Gathering Information	p. 337
Displaying the Information	p. 339
Final Thoughts	p. 340
Developing COM+ Transactions	p. 343
Developing COM+ Transactions for SQL Server	p. 345
Designing the Contact Manager Application	p. 346
Middle Tier Design	p. 346
Client Application Design	p. 347
Communicating Using Objects	p. 349
The Contacts Collection	p. 350
The Contact Object	p. 352
The ContactInfos Collection	p. 353
The ContactInfo Object	p. 354
The ActionItems Collection	p. 354
The ActionItem Object	p. 355
Programming the Contact Manager Application	p. 355
Getting Information about a Contact	p. 356
Connecting to the Database	p. 360
Updating the Contact Information	p. 361
Finding a Client	p. 364
Final Thoughts	p. 369
Developing COM+ Transactions for IIS Applications	p. 373
Moving ContactManager to the Web	p. 374
Understanding IIS Applications	p. 375
How IIS Applications Work	p. 375
The IIS Application Object Model	p. 376
Programming the Main Web Page	p. 377
Starting the Application	p. 378
Displaying the Main Web Page	p. 379
Processing the Main Web Page	p. 384
Programming the Details Web Page	p. 386
Displaying the Details Web Page	p. 387
Processing the Details Web Page	p. 392
Using the Contact Manager Transactions	p. 395
The PutContactInfos Method	p. 396
The PutAContactInfo Method	p. 397
The PutActionItems Method	p. 399
The PutAnActionItem Method	p. 400
Final Thoughts	p. 402
Developing COM+ Transactions for MSMQ	p. 405
Application Design	p. 406
Design Issues	p. 406
Design Concept	p. 407
Programming the Contact Client	p. 407
Keeping Local Information	p. 407
Requesting Data	p. 410
Receiving Data	p. 414
Updating Data	p. 416
Programming the ContactQueue Manager	p. 417
Processing a Request	p. 417
Returning a Response	p. 419
Programming ContactTypes	p. 420
Using the Request Object	p. 420
Making the ActionItems Object Persistent	p. 421
Final Thoughts	p. 426
Glossary	p. 429
Index	p. 441
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