book

VB.NET Language in a Nutshell, Second Edition

by Steven Roman PhD, Ron Petrusha, Paul Lomax

April 2002

Intermediate to advanced

688 pages

19h 51m

English

O'Reilly Media, Inc.

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Getting a VB Program to RunConsole ApplicationsWindows Forms Applications
Events: The Starting PointWindows Forms eventsASP.NET eventsEvent argumentsCalling Routines from Event HandlersWriting Custom ProceduresFunctionsSub proceduresProperty proceduresControlling Execution FlowCalling sub and function proceduresSetting and retrieving property values
VariablesVariable ScopeLocal variables: block-level and procedure-level scopeModule-level and project-level scopePrivate accessFriend accessPublic accessVariable LifetimeStatic variables
Value and Reference TypesVB Data Types: A SummarySimple Data Types in Visual BasicBoolean data typeByte data typeChar data typeDate data typeDecimal data typeDouble data typeInteger data typeLong data typeObject data typeShort data typeSingle data typeString data typeStructure data type: user-defined typesData Type Conversion
Definition of ArrayDimension of an ArraySize of an ArrayArrays in VB.NETRedimensioning arrays
Late Binding Versus Early Binding
Passing ArgumentsPassing ObjectsOptional ArgumentsParamArray
Why Learn Object-Oriented Techniques?
AbstractionEncapsulationInterfaces
Class Modules in VB.NETClass MembersThe Public Interface of a VB.NET ClassObjectsPropertiesInstance and Shared MembersClass ConstructorsFinalize, Dispose, and Garbage Collection
Permission to InheritOverridingRules of InheritanceMyBase, MyClass, and MeShadowing
Interfaces Revisited
OverloadingPolymorphism
Member InheritanceMember Accessibility
Namespaces
The System NamespaceData Type ConversionThe Array ClassThe Math ClassThe String Class
System.CollectionsSystem.DataSystem.IOSystem.Text.RegularExpressionsSystem.Windows.Forms
DelegatesUsing a Delegate to Call a MethodUsing a Delegate as a Function Pointer
Control-Related EventsWithEventsAddHandler and RemoveHandler
Syntax and Use
Error Detection and Error Handling
Unstructured Error HandlingThe Err objectDealing with runtime errorsIn-line error handlingCentralized error handlingNo enabled error-handlerStructured Exception HandlingTry...Catch...FinallyException classes
Detecting Logical ErrorsWhere to Handle a Logical ErrorHandling the error on the spotHandling the error in the offending procedure’s error handlerPassing the error to the calling procedure
Language Changes for VB.NETData TypesStringsInteger/Long data type changesVariant data typeOther data type changesVariables and Their DeclarationVariable declarationVariable initializationVariable scope changesArrays and array declarationsStructure/user-defined type declarationsBoolean and Bitwise OperatorsChanges Related to ProceduresCalling a procedureDefault method of passing argumentsOptional argumentsReturn statementPassing property parameters in proceduresParamArray parametersMiscellaneous Language ChangesLine numbersOn GoToWhileGoSub and Return statements
ConstantsString FunctionsEmptinessGraphical FunctionalityMathematical FunctionalityDiagnosticsMiscellaneous
InheritanceOverloadingObject CreationPropertiesDefault propertiesProperty declarations
Array Handling
Data Type ConversionOther Conversion
Object ProgrammingMiscellaneous Programming
Arithmetic Operators
The Is OperatorThe Like Operator
Visual Basic Intrinsic Constants
AppWinStyle EnumerationCallType EnumerationCompareMethod EnumerationDateFormat EnumerationDateInterval EnumerationDueDate EnumerationFileAttribute EnumerationFirstDayOfWeek EnumerationFirstWeekOfYear EnumerationMsgBoxResult EnumerationMsgBoxStyle EnumerationOpenAccess EnumerationOpenMode EnumerationOpenModeTypes EnumerationOpenShare EnumerationTriState EnumerationVariantType EnumerationVbStrConv Enumeration
Compiler Basics
Output Filename and File TypeInput FilesResourcesCode GenerationDebuggingErrors and WarningsLanguageMiscellaneousAdvanced

Content preview from VB.NET Language in a Nutshell, Second Edition

Changes in Object-Orientation

As you may know, Visual Basic has implemented some features of object-oriented programming since Version 4. However, in terms of object-orientation, the step from Version 6 to VB.NET is very significant. Indeed, some people did not consider VB 6 (or earlier versions) to be a truly object-oriented programming language. Whatever your thoughts may have been on this matter, it seems clear that VB.NET is an object-oriented programming language by any reasonable definition of that term.

Here are the main changes in the direction of object-orientation. We discuss these issues in detail in Chapter 4.

Inheritance

VB.NET supports object-oriented inheritance (but not multiple inheritance). This means that a class can derive from another (base) class, thereby inheriting all of the properties, methods, and events of the base class. Since forms are also classes, inheritance applies to forms as well. This allows new forms to be created based on existing forms. We discuss inheritance in detail in Chapter 4.

Overloading

VB.NET supports a language feature known as function overloading. The idea is simple and yet quite useful. We can use the same name for different functions (or subroutines), as long as the functions can be distinguished by their argument signature. The argument signature of a function (or subroutine) is the sequence of data types of the arguments of the function. Thus, in order for two functions to have the same argument signature, they must have the ...