.NET Whirlwind Intro for Rice

1. .NET Whirlwind Introfor Rice Michael StuartSr. Consultantmstuart@microsoft.comWill Rice class of 1991 Chris WaferLowly Consultantcwafer@microsoft.comJones class of 2000

2. Outline • Who are we? (not an existential conundrum) • What is .NET? • Marketing mantra vs. reality • Platform…for web services • Tools—Visual Studio • 2002 vs. 2003, RTM vs. Everett vs. Whidbey • Mongo debugging, templates, visual designers • .NET Framework Overview • CLR, CTS, CLI • OO, JIT, GC • Practical development with .NET • OO, design patterns • Mobile development • .NET CF (Compact Framework) • Web Services • Questions

3. Who are we? • Chris— • Recent Rice grad, real CS not flaky other pseudo-science • Consultant at Microsoft in South Region • Specializes in .NET development • Fingers possessed by l33t hax0rs of yore • Thinks M3 is faster than M-Coupe, too young to know better • Michael— • Lovable but slightly addled uncle-type • Old Rice grad—Biochem/Bio+PoliSci, M.D. • Hacker of old, cut teeth in 6502 Assembler • Specialized in .NET dev • Currently working with PAG team on patterns

4. What is .NET? • Marketing mantra vs. reality • .NET Framework—Visual Studio, actual runtime, languages, web services are _really_ “.NET” • “.NET Servers”—are .NET enabled but not necessarily written in .NET (CS2k, BizTalk…) • Platform…for web services • Much more to-the-point: .NET is a platform for Web Services • Other • Loosely-coupled programming model • New paradigm for Microsoft-based developers • Much easier to write good code • Focus on logic, not plumbing—we’ll wear the plumber jeans 

5. Tools • 2002 vs. 2003, RTM vs. Everett vs. Whidbey • VS.NET—complete tool for developing .NET (and old-school) software • Encompasses all languages—C#, VB.NET, J#, 20+ others • RTM—Framework v. 1.0.3705 • Everett—currently beta, v. 1.1.4322 • Whidbey—future, big changes (generics, built-in patterns, etc.) • Mongo debugging, templates, visual designers • Debugging—over the river, through the woods… • Templates—strong future • Designers—beloved RAD tools, beefier underpinnings now

6. .NET Framework Overview • CLR, CTS, CLI • OO, JIT, GC

7. .NET Framework Overview 2Infrastructure for the .NET Platform • Common Language Runtime • Manages running code • Verifies type safety • Provides garbage collection, error handling, threading • Security • Provides common type system • Provides access to system resources • Native API, COM interop, etc. • A collection of unified classes

8. .NET Framework Overview 3Win32 and the .NET Framework Unified Class libraries Unifies Programming models across languages Factored for extensibility Designed for tools C# Visual J#... Visual Basic .NET Enterprise Services ASP.NET ADO.NET Enterprise Services The services required for mission critical applications: Transactions, Messaging, Partitions, Object Pooling and Events COM: Not Dead Yet CLR XML and Data Access ADO .NET interfaces any database, loosely coupled data access and native XML data format; leverages the huge library of ODBC OLE DB drivers Active Directory MSMQ COM+ IIS WMI Win32 CLR Executes code, maintains security, handles component “plumbing” and dependencies XML Web Services and Scripting High-productivity environmentfor building and operating XML Web services

9. .NET Framework Overview 3CLR Duties • Manages running code • Threading • Memory management / GC • JIT to native • COM Interop • Security, type safety, bounds checks, assembly loading, remoting, etc. (all runtime stuff) • Fine-grained evidence-based security • Code access security • IL can be verified to guarantee type safety • No unsafe casts, no un-initialized variables and no out-of-bounds array indexing • Role-based security • Integrated with underlying OS

10. Code Source Code Language Compiler MSIL Metadata Execution Native Code JIT Compiler .NET Framework Overview 4Compilation and Execution ILDASM! IL_000c: br.s IL_002a IL_000e: ldloc.1 IL_000f: callvirt instance object [mscorlib]System.Collections.IEnumerator::get_Current() IL_0014: castclass [mscorlib]System.String IL_0019: stloc.0 IL_001a: ldstr "Flea's name : " Compilation Before execution (ngen) or the first time each method is called

11. .NET Framework Overview 4Simplified Development • Eliminates COM plumbing • No more … • Registration • GUIDs • .IDL files • HRESULTs • IUnknown • AddRef/Release • CoCreateInstance =>self describing components =>hierarchical namespaces =>source code to metadata =>structured exceptions =>root object class =>garbage collector =>”new” operator

12. Practical Development with .NET • Demo—how to set up quickie web service (asmx) • Demo—web-service-based Forth calculator • Demo—Interfaces and Abstracts • Demo—Virtual vs. Non-Virtual calls • Debugging down to the metal: • Memory view • Register view • X86 ASM view • Demo—delegates and events • Demo—how to screw up Boxing/Unboxing • Demo—UIP “pet project” • Demo—database access application (??)

13. Practical Development with .NET • Demo—how to set up quickie web service (asmx) • Basic web service requires ASMX file + code • ASP.NET HttpModule hooks up ASMX to code • Compiles and JIT’s code • Generates WSDL dynamically (SOAP contract) • Core syntax: • <%@ WebService Language="c#" Class="Calculator " %> • [WebMethod] • (try THAT in J2EE  )

14. Practical Development with .NET • Demo—web-service-based Forth calculator • Now consume the calculator web service we made • Uses stack-based calc • Uses Compact Framework • Accesses web service from Pocket PC device • Note use of derived stack— • IN FUTURE FRAMEWORK, GENERICS will do this 

15. Practical Development with .NET • Demo—Interfaces and Abstracts • .NET supports • Multiple interface implementation • Single inheritance—NO multiple inheritance • Abstract base class • Base functionality • Not instantiable • Good use: “is a kind of”, abstract entity meaningless— • Mammal abstract base—but there’s no plain “mammal” animal • Lion : Mammal—concrete derivative has meaning but borrows basic functionality such as sleep, heartbeat from abstract • Interface implementation • Heavy use of “marker” interfaces in .NET (IDisposable) • Provides strict contractual obligation • No base functionality

16. Practical Development with .NET • Demo—Virtual vs. Non-Virtual calls • Non-default virtual in .NET • Public void Foo() in class A • Public new void Foo() in Class B : A • B.Foo does B.Foo; ((A)B).Foo does A.Foo • Public virtual void Foo() in class C • Public override void Foo() in Class D : C • D.Foo does D.Foo; ((C)D).Foo STILL does D.Foo • Be careful of deep inheritance chains • If middle of chain does “new”, THAT is where it stops! • UNLESS you play games with versioning • .NET avoids “Base Class Fragility” with versioning!

17. Practical Development with .NET • Demo—delegates and events • Fundamental Rule #1: • “A Delegate is a Type-Safe Function Pointer!” • James Gosling (father of Java) calls Anders Heljsberg “Mr. Function Pointers” • Anders is too polite to respond  • Delegate syntax: • public delegate void DoneCookingDelegate(); • Delegates are always multi-cast; you can chain them up • Delegates can be declared anywhere; if they’re accessible they’re good • Delegates point to a concrete endpoint that matches signatures • EVENTS in .NET are special-case delegates

18. Practical Development with .NET • Demo—how to screw up Boxing/Unboxing • How is .NET so FAST? • Singly-rooted hierarchy; • ALL objects derive from System.Object—ints, strings, doubles, even kids with chickenpox • An Int32 is an object if you treat it like one, otherwise it’s stack-allocated • Value Types vs. Reference Types • Value types go on stack—int, double, long, struct, double, decimal, uint, etc. • Reference types are officially objects all the time and go on HEAP • .NET can BOX—convert value type to ref type • .NET can UNBOX—convert ref to value • Be Careful—boxing implicit, unboxing explicit

19. QUESTIONS???

20. Thank you all Very Much!Michael Stuart—mstuart@microsoft.comChris Wafer—cwafer@microsoft.com