What’s new in VB .NET

1. What’s new in VB .NET adapted from a presentation on Introduction to Visual Basic .NET by Jeff Quasney Course Technology

3. An Overview

4. What’s 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

5. What’s 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

6. What’s 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

7. Application Types • Console Applications

8. Application Types • Windows Applications

9. Application Types • Windows Services

10. Application Types • Web Applications

11. Application Types • Web Services

12. Application Types • Components

13. What is .NET?

14. .NET Framework

15. 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

16. The Common Language Runtime • Takes control of the application and runs the application under the operating system • Microsoft Intermediate Language (MSIL)

17. The Common Language Runtime • MSIL is CPU/OS independent • Compile once for multiple CPU’s/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

18. The Common Language Runtime • Registration info no longer in registry • Meta data stored in assemblies • Only distribute assembly • .NET Framework required on user’s system • Memory management • Exception handling • No IDL, no registration, no HRESULTS, no GUIDs, • Replaces all COM plumbing

19. What’s New in VB .NET?

20. 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

21. 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

22. 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

23. 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!”)

24. 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

25. About Loops • While…Wend changed to While…End While

26. 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!

27. 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.

28. About Operators • New concatenation operators +, -, *, /, & intI += 100 intl -= 100

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

30. About Menus and Help • Menu editor • Create a menu and a context menu • Help • Dynamic help is addictive

31. 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

32. What’s 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() • Don’t assume you know when destructor is called

33. What’s new in Databases? • Too much to mention • ADO.NET • SqlClient namespace vs. OleDB namespace • DataSet and DataTable • DataReader • Plea/Editorial: Please don’t use Data controls

34. What will make you scratch your head? • Line numbers are messed up • Can’t print a form in design mode for a Windows form, but you CAN for a Web form • Value of True (non-zero, not 1)

35. The End