Visual Basic 2005 Recipes

Transcription

1 The EXPERT s VOIce in.net Visual Basic 2005 Recipes A Problem-Solution Approach Learn practical solutions for your VB 2005 problems. Todd Herman, Allen Jones, Matthew MacDonald, and Rakesh Rajan

2 Visual Basic 2005 Recipes A Problem-Solution Approach Todd Herman, Allen Jones, Matthew MacDonald, and Rakesh Rajan

3 Visual Basic 2005 Recipes: A Problem-Solution Approach Copyright 2007 by Todd Herman, Allen Jones, Matthew MacDonald, Rakesh Rajan All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher. ISBN-13 (pbk): ISBN-10 (pbk): Printed and bound in the United States of America Trademarked names may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, we use the names only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. Lead Editor: Ewan Buckingham Technical Reviewer: Damien Foggon Editorial Board: Steve Anglin, Ewan Buckingham, Gary Cornell, Jonathan Gennick, Jason Gilmore, Jonathan Hassell, Chris Mills, Matthew Moodie, Jeffrey Pepper, Ben Renow-Clarke, Dominic Shakeshaft, Matt Wade, Tom Welsh Project Manager: Beth Christmas Copy Edit Manager: Nicole Flores Copy Editor: Marilyn Smith Assistant Production Director: Kari Brooks-Copony Production Editor: Ellie Fountain Compositor: Susan Glinert Proofreader: Liz Welch Indexer: John Collin Artist: Kinetic Publishing Services, LLC Cover Designer: Kurt Krames Manufacturing Director: Tom Debolski Distributed to the book trade worldwide by Springer-Verlag New York, Inc., 233 Spring Street, 6th Floor, New York, NY Phone SPRINGER, fax , orders-ny@springer-sbm.com, or visit For information on translations, please contact Apress directly at 2855 Telegraph Avenue, Suite 600, Berkeley, CA Phone , fax , info@apress.com, or visit The information in this book is distributed on an as is basis, without warranty. Although every precaution has been taken in the preparation of this work, neither the author(s) nor Apress shall have any liability to any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectly by the information contained in this work. The source code for this book is available to readers at in the Source Code/Download section.

4 This book is for my incredible wife and best friend Amy, as well as my son Aidan and daughter Alaina. Without them I wouldn t be the man I am today and this book may not have been possible. Todd Herman

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6 Contents at a Glance About the Authors xv About the Technical Reviewer xvii Acknowledgments xix Introduction xxi CHAPTER 1 Application Development CHAPTER 2 Data Manipulation CHAPTER 3 Application Domains, Reflection, and Metadata CHAPTER 4 Threads, Processes, and Synchronization CHAPTER 5 Files, Directories, and I/O CHAPTER 6 XML Processing CHAPTER 7 Windows Forms CHAPTER 8 Multimedia CHAPTER 9 Database Access CHAPTER 10 Networking and Remoting CHAPTER 11 Security and Cryptography CHAPTER 12 Unmanaged Code Interoperability CHAPTER 13 Commonly Used Interfaces and Patterns CHAPTER 14 Windows Integration CHAPTER 15 Language Integrated Query (LINQ) APPENDIX Acronyms Index v

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8 Contents About the Authors xv About the Technical Reviewer xvii Acknowledgments xix Introduction xxi CHAPTER 1 Application Development Create a Console Application from the Command Line Create a Windows-Based Application from the Command Line Create and Use a Code Module from the Command Line Create and Use a Code Library from the Command Line Access Command-Line Arguments Include Code Selectively at Build Time Access a Program Element That Has the Same Name As a Keyword Create and Manage Strong-Named Key Pairs Give an Assembly a Strong Name Verify That a Strong-Named Assembly Has Not Been Modified Delay Sign an Assembly Sign an Assembly with an Authenticode Digital Signature Create and Trust a Test Software Publisher Certificate Manage the Global Assembly Cache Make Your Assembly More Difficult to Decompile Manipulate the Appearance of the Console Embed a Resource File in an Assembly CHAPTER 2 Data Manipulation Manipulate the Contents of a String Efficiently Encode a String Using Alternate Character Encoding Convert Basic Value Types to Byte Arrays Base64 Encode Binary Data Validate Input Using Regular Expressions Use Compiled Regular Expressions vii

9 viii CONTENTS 2-7. Create Dates and Times from Strings Add, Subtract, and Compare Dates and Times Sort an Array or an ArrayList Copy a Collection to an Array Use a Strongly Typed Collection Create a Generic Type Store a Serializable Object to a File Read User Input from the Console CHAPTER 3 Application Domains, Reflection, and Metadata Load an Assembly into the Current Application Domain Create an Application Domain Execute an Assembly in a Different Application Domain Avoid Loading Unnecessary Assemblies into Application Domains Create a Type That Cannot Cross Application Domain Boundaries Create a Type That Can Be Passed Across Application Domain Boundaries Instantiate a Type in a Different Application Domain Pass Data Between Application Domains Unload Assemblies and Application Domains Retrieve Type Information Test an Object s Type Instantiate an Object Using Reflection Create a Custom Attribute Inspect the Attributes of a Program Element Using Reflection CHAPTER 4 Threads, Processes, and Synchronization Execute a Method Using the Thread Pool Execute a Method Asynchronously Execute a Method Periodically Execute a Method at a Specific Time Execute a Method by Signaling a WaitHandle Object Execute a Method Using a New Thread Synchronize the Execution of Multiple Threads Using a Monitor

10 CONTENTS ix 4-8. Synchronize the Execution of Multiple Threads Using an Event Synchronize the Execution of Multiple Threads Using a Mutex Synchronize the Execution of Multiple Threads Using a Semaphore Synchronize Access to a Shared Data Value Know When a Thread Finishes Terminate the Execution of a Thread Create a Thread-Safe Collection Instance Start a New Process Terminate a Process Ensure That Only One Instance of an Application Can Execute Concurrently CHAPTER 5 Files, Directories, and I/O Retrieve Information About a File, Directory, or Drive Set File and Directory Attributes Copy, Move, or Delete a File or a Directory Calculate the Size of a Directory Retrieve Version Information for a File Show a Just-in-Time Directory Tree in the TreeView Control Read and Write a Text File Read and Write a Binary File Parse a Delimited Text File Read a File Asynchronously Find Files That Match a Wildcard Expression Test Two Files for Equality Manipulate Strings Representing Filenames Determine If a Path Is a Directory or a File Work with Relative Paths Create a Temporary File Get the Total Free Space on a Drive Show the Common File Dialog Boxes Use an Isolated Store Monitor the File System for Changes Access a COM Port Get a Random Filename Manipulate the Access Control Lists of a File or Directory

11 x CONTENTS CHAPTER 6 XML Processing Show the Structure of an XML Document in a TreeView Insert Nodes in an XML Document Quickly Append Nodes in an XML Document Find Specific Elements by Name Get XML Nodes in a Specific XML Namespace Find Elements with an XPath Search Read and Write XML Without Loading an Entire Document into Memory Validate an XML Document Against a Schema Use XML Serialization with Custom Objects Create a Schema for a.net Class Generate a Class from a Schema Perform an XSL Transform CHAPTER 7 Windows Forms Add a Control Programmatically Link Data to a Control Process All the Controls on a Form Track the Visible Forms in an Application Find All MDI Child Forms Save Configuration Settings for a Form Force a List Box to Scroll to the Most Recently Added Item Restrict a Textbox to Accepting Only Specific Input Use an Autocomplete Combo Box Sort a List View by Any Column Lay Out Controls Automatically Use Part of a Main Menu for a Context Menu Make a Multilingual Form Create a Form That Cannot Be Moved Make a Borderless Form Movable Create an Animated System Tray Icon Validate an Input Control Use a Drag-and-Drop Operation Use Context-Sensitive Help Display a Web Page in a Windows-Based Application

12 CONTENTS xi CHAPTER 8 Multimedia Find All Installed Fonts Perform Hit Testing with Shapes Create an Irregularly Shaped Control Create a Movable Sprite Create a Scrollable Image Perform a Screen Capture Use Double Buffering to Increase Redraw Speed Show a Thumbnail for an Image Play a Simple Beep or System Sound Play a WAV File Play a Sound File Show a Video with DirectShow Retrieve Information About Installed Printers Print a Simple Document Print a Multipage Document Print Wrapped Text Show a Dynamic Print Preview Manage Print Jobs CHAPTER 9 Database Access Connect to a Database Use Connection Pooling Create a Database Connection String Programmatically Store a Database Connection String Securely Execute a SQL Command or Stored Procedure Use Parameters in a SQL Command or Stored Procedure Process the Results of a SQL Query Using a Data Reader Obtain an XML Document from a SQL Server Query Perform Asynchronous Database Operations Against SQL Server Write Database-Independent Code Discover All Instances of SQL Server on Your Network CHAPTER 10 Networking and Remoting Obtain Information About the Local Network Interface Detect Changes in Network Connectivity Download Data over HTTP or FTP

13 xii CONTENTS Download a File and Process It Using a Stream Respond to HTTP Requests from Your Application Get an HTML Page from a Site That Requires Authentication Send Using SMTP Resolve a Host Name to an IP Address Ping an IP Address Communicate Using TCP Create a Multithreaded TCP Server That Supports Asynchronous Communications Communicate Using UDP Avoid Hard-Coding the Web Service URL Set Authentication Credentials for a Web Service Call a Web Method Asynchronously Make an Object Remotable Register All the Remotable Classes in an Assembly Host a Remote Object in IIS Control the Lifetime of a Remote Object Control Versioning for Remote Objects CHAPTER 11 Security and Cryptography Allow Partially Trusted Code to Use Your Strong-Named Assembly Disable Code Access Security Disable Execution Permission Checks Ensure the Runtime Grants Specific Permissions to Your Assembly Limit the Permissions Granted to Your Assembly View the Permissions Required by an Assembly Determine at Runtime If Your Code Has a Specific Permission Restrict Who Can Extend Your Classes and Override Class Members Inspect an Assembly s Evidence Determine If the Current User Is a Member of a Specific Windows Group Restrict Which Users Can Execute Your Code Impersonate a Windows User

14 CONTENTS xiii Create a Cryptographically Random Number Calculate the Hash Code of a Password Calculate the Hash Code of a File Verify a Hash Code Ensure Data Integrity Using a Keyed Hash Code Work with Security-Sensitive Strings in Memory Encrypt and Decrypt Data Using the Data Protection API CHAPTER 12 Unmanaged Code Interoperability Call a Function in an Unmanaged DLL Get the Handle for a Control, Window, or File Call an Unmanaged Function That Uses a Structure Call an Unmanaged Function That Uses a Callback Retrieve Unmanaged Error Information Use a COM Component in a.net Client Release a COM Component Quickly Use Optional Parameters Use an ActiveX Control in a.net Client Expose a.net Component to COM CHAPTER 13 Commonly Used Interfaces and Patterns Implement a Serializable Type Implement a Cloneable Type Implement a Comparable Type Implement an Enumerable Type Using a Custom Iterator Implement a Disposable Class Implement a Formattable Type Implement a Custom Exception Class Implement a Custom Event Argument Implement the Singleton Pattern Implement the Observer Pattern CHAPTER 14 Windows Integration Access Runtime Environment Information Retrieve the Value of an Environment Variable Write an Event to the Windows Event Log Read and Write to the Windows Registry

15 xiv CONTENTS Search the Windows Registry Create a Windows Service Create a Windows Service Installer Create a Shortcut on the Desktop or Start Menu CHAPTER 15 Language Integrated Query (LINQ) Use Implicitly Typed Variables Use Object Initializers Use Anonymous Types Create Extension Methods Query an IEnumerable(Of T) Collection Query a Nongeneric Collection Sort Data Using LINQ Filter Data Using LINQ Query Data from Multiple Collections Perform Aggregate Operations on Collections Retrieve a Subset of Data from a Collection Display Collection Data Using Paging APPENDIX Acronyms INDEX

16 About the Authors TODD HERMAN works for Northrop Grumman developing software for the Department of State. He has been programming since he received his first computer, a Commodore 64, on his eleventh birthday. His experience ranges from developing data-entry software in FoxPro for a water research laboratory to writing biometric applications in Visual Basic for NEC. He currently lives in Virginia with his wife and children, and spends his free time programming, playing games, and watching the Sci-Fi channel. ALLEN JONES has 15 years of experience covering a wide range of IT disciplines in a variety of sectors; however, his true passion has always been software development. Allen is currently Director of Product Development at Smith- Bayes, a UK-based firm that develops high-end, strategic-decision-support software derived from technology used in Formula 1 motor racing. MATTHEW MACDONALD is an author, educator, and Microsoft MVP. He is a regular contributor to programming journals and the author of more than a dozen books about.net programming, including Pro.NET 2.0 Windows Forms and Custom Controls in C#, Pro ASP.NET 2.0, and Pro WPF (each published by Apress). In a dimly remembered past life, he studied English literature and theoretical physics. RAKESH RAJAN coauthored an earlier book on which this book is based (Visual C# 2005 Recipes, Apress, 2006). Sadly, Rakesh passed away in He was a Microsoft MVP in C# and an MCSD in.net. As a software engineer from India, Rakesh worked with US Technology at Technopark, Trivandrum in Kerala. xv

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18 About the Technical Reviewer DAMIEN FOGGON is a freelance programmer and technical author based in Newcastle, England. He is technical director of Thing-E Ltd., a company specializing in the development of dynamic web solutions for the education sector, and founder of Littlepond Ltd. He started out working for BT in the UK before moving on to progressively smaller companies, finally founding his own company. Now he can work on all the cool new technologies, rather than the massive monolithic developments that still exist out there. Damien is the author of Beginning ASP.NET 2.0 Databases: From Novice to Professional (Apress, 2006). He can be reached at xvii

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20 Acknowledgments I first want to thank Richard Guidorizzi for reaffirming my thoughts regarding writing a book. Furthermore, I must thank Ewan Buckingham for seeing something in my and offering me the opportunity to write this. Finally, I must also extend my thanks and appreciation to Damien Foggon, my technical reviewer. His comments and suggestions forced me to dig deeper into myself and the material to make this a book to be proud of. Todd Herman xix