Whats new in VB .NET

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Whats new in VB .NET

• adapted from a presentation on
• Introduction to
• Visual Basic .NET
• by
• Jeff Quasney
• Course Technology

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(No Transcript)
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An Overview
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Whats New in Visual Studio .NET?

• IDE (Start page, common for ALL .NET languages)
• Application templates
• New editing tools (HTML, XML, XSL, CSS)
• Cross-language debugging, Multiple languages per
  Solution
• New sample apps and documentation
• Strong focus on XML

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Whats New in Microsoft Visual Basic .NET?

• VB .NET was a rewrite, not an update
• New/changed data types
• No Variant, CTS
• New/changed syntax
• Dim, assignment, arrays, keywords
• Application distribution

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Whats New in Microsoft Visual Basic .NET?
(continued)

• Inheritance
• Exception handling (Structured exception
  handling)
• Overloading
• Multithreading
• Web development
• Web services
• Web applications (ASP.NET)
• ADO.NET

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Application Types

• Console Applications

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Application Types

• Windows Applications

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Application Types

• Windows Services

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Application Types

• Web Applications

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Application Types

• Web Services

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Application Types

• Components

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What is .NET?
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.NET Framework
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Why .NET?

• Common classes
• Common security model
• DLL H E double-toothpicks gone?
• Side-by-side execution
• Garbage collection
• Multi-platform?
• New application types
• Language interoperability

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The Common Language Runtime

• Takes control of the application and runs the
  application under the operating system
• Microsoft Intermediate Language (MSIL)

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The Common Language Runtime

• MSIL is CPU/OS independent
• Compile once for multiple CPUs/platforms
• Take an EXE and run it on Linux
• Ximian (?) is working on this
• Assembly and manifest concept
• Xcopy installs
• Side-by-side execution
• Logically, all EXEs and DLLs act as DLLs

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The Common Language Runtime

• Registration info no longer in registry
• Meta data stored in assemblies
• Only distribute assembly
• .NET Framework required on users system
• Memory management
• Exception handling
• No IDL, no registration, no HRESULTS, no GUIDs,
• Replaces all COM plumbing

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Whats New in VB .NET?
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About Procedures

• Subs and functions need parentheses
• Use
• MyProc(A parameter)
• Not
• MyProc A parameter
• ByVal is now the default!
• Optional arguments need a default value
• Sub DoWork(Optional ByVal i As Integer 1)
• Return is used in Functions to return a value

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About IF Statements

• AndAlso and OrElse do short-circuiting
• If intX 1 AndAlso intY 2 Then
• In above example, second expression is not
  evaluated if intX is not 1

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About Object Declarations

• OLD
• Dim objCustomer As Store.Customer
• Set objCustomer New Store.Customer
• NEW
• Imports Store
• Dim objCustomer New Customer
• OR
• Dim objCustomer as Customer New Customer

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About Scope

• New Block-level Scope
• Dim intX As Integer
• For intX 1 To 5
• Dim intZ As Integer
• MessageBox.Show(Scope is important.)
• Next intX
• MessageBox.Show(intZ is out of scope!)

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About Arrays

• Lower bound is always zero
• Dim intA(5 To 8) no longer is possible
• Option Base is gone as well
• Arrays have VERY useful methods
• Declare arrays by upperbound, not size Same as
  VB6
• Dim strX(10) As String contains 11 elements
• Setting an array to another array is now done by
  reference
• In VB6, this was done by value
• Use Copy method of arrays to make an actual copy

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About Loops

• WhileWend changed to WhileEnd While

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About Data Types

• All variables are objects. Variants are gone.
• Type a period after any variable in the IDE to
  see methods/properties
• Strings are never fixed length. They are
  destroyed and recreated by the CLR when value
  changes
• Only one type of string variable for ALL
  languages
• No Currency data type. Now decimal.
• UDTs are gone
• Use structures instead
• Structure statement replaces Type
• Structures support methods!

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Useful Options

• Option Strict On
• Forces declarations
• Forces data types to be same on both sides of
• Use it always. Get in the habit. Force your
  students to use it in assignments.

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About Operators

• New concatenation operators
• , -, , /,
• intI 100
• intl - 100

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About Controls

• Default properties of controls are GONE
• New way to set tab order
• Shape controls are gone
• Use System.Drawing namespace

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About Menus and Help

• Menu editor
• Create a menu and a context menu
• Help
• Dynamic help is addictive

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Misc

• New control alignment tools
• New properties
• Anchoring and AutoSize
• Opacity of forms
• Printing
• Several new, powerful printing controls
• Print controls/objects get more complicated, but
  more powerful
• Crystal Reports is included with
  Professional/Academic versions
• New way to set tab order

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Whats new in OO?

• Too much to mention
• Inheritance
• Polymorphism
• New syntax for creating properties
• Read-only, Write-only properties
• Aggregation is weird, though (just in VB)
• Constructor Sub New() Destructor Sub
  Finalize()
• Dont assume you know when destructor is called

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Whats new in Databases?

• Too much to mention
• ADO.NET
• SqlClient namespace vs. OleDB namespace
• DataSet and DataTable
• DataReader
• Plea/Editorial Please dont use Data controls

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What will make you scratch your head?

• Line numbers are messed up
• Cant print a form in design mode for a Windows
  form, but you CAN for a Web form
• Value of True (non-zero, not 1)

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• The End