.NET Whirlwind Intro
for Rice
Michael Stuart
Sr. Consultant
[email protected]
Will Rice class of 1991
Chris Wafer
Lowly Consultant
[email protected]
Jones class of 2000
Outline
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Who are we? (not an existential conundrum)
What is .NET?
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Tools—Visual Studio
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OO, design patterns
Mobile development
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CLR, CTS, CLI
OO, JIT, GC
Practical development with .NET
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2002 vs. 2003, RTM vs. Everett vs. Whidbey
Mongo debugging, templates, visual designers
.NET Framework Overview
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Marketing mantra vs. reality
Platform…for web services
.NET CF (Compact Framework)
Web Services
Questions
Who are we?
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Chris—
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Recent Rice grad, real CS not flaky other pseudoscience
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—
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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
What is .NET?
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Marketing mantra vs. reality
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Platform…for web services
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.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…)
Much more to-the-point: .NET is a platform for Web
Services
Other
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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 
Tools
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2002 vs. 2003, RTM vs. Everett vs. Whidbey
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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
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Debugging—over the river, through the woods…
Templates—strong future
Designers—beloved RAD tools, beefier
underpinnings now
.NET Framework Overview
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CLR, CTS, CLI
OO, JIT, GC
.NET Framework Overview 2
Infrastructure for the .NET Platform
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Common Language Runtime
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Manages running code
Verifies type safety
Provides garbage collection, error handling,
threading
Security
Provides common type system
Provides access to system resources
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Native API, COM interop, etc.
A collection of unified classes
.NET Framework Overview 3
Win32 and the .NET Framework
C#
Visual Basic .NET
ASP
.NET
ADO
.NET
Enterprise
Services
COM: Not
Dead Yet
CLR
MSMQ
Visual J#...
COM+
Active
Directory
IIS
Win32
CLR
Executes code, maintains
security, handles component
“plumbing” and dependencies
WMI
Unified Class libraries
Unifies Programming
models across languages
Factored for extensibility
Designed for tools
Enterprise Services
The services required for mission
critical applications: Transactions,
Messaging, Partitions, Object
Pooling and Events
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
XML Web Services and Scripting
High-productivity environment
for building and operating XML
Web services
.NET Framework Overview 3
CLR Duties
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Manages running code
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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
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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
.NET Framework Overview 4
ILDASM!
Compilation and Execution
Compilation
Source
Code
Language
Compiler
Code
Metadata
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 : "
MSIL
Execution
Native
Code
JIT
Compiler
Before
execution
(ngen) or the
first time each
method is called
.NET Framework Overview 4
Simplified Development
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Eliminates COM
plumbing
No more …
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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
Practical Development with .NET
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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
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Debugging down to the metal:
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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 (??)
Practical Development with .NET
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Demo—how to set up quickie web service
(asmx)
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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:
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<%@ WebService Language="c#" Class="Calculator " %>
[WebMethod]
(try THAT in J2EE  )
Practical Development with .NET
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Demo—web-service-based Forth calculator
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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—
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IN FUTURE FRAMEWORK, GENERICS will do this 
Practical Development with .NET
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Demo—Interfaces and Abstracts
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.NET supports
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Abstract base class
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Base functionality
Not instantiable
Good use: “is a kind of”, abstract entity meaningless—
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Multiple interface implementation
Single inheritance—NO multiple inheritance
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
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Heavy use of “marker” interfaces in .NET (IDisposable)
Provides strict contractual obligation
No base functionality
Practical Development with .NET
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Demo—Virtual vs. Non-Virtual calls
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Non-default virtual in .NET
Public void Foo() in class A
Public new void Foo() in Class B : A
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Public virtual void Foo() in class C
Public override void Foo() in Class D : C
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D.Foo does D.Foo; ((C)D).Foo STILL does D.Foo
Be careful of deep inheritance chains
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B.Foo does B.Foo; ((A)B).Foo does A.Foo
If middle of chain does “new”, THAT is where it stops!
UNLESS you play games with versioning
.NET avoids “Base Class Fragility” with versioning!
Practical Development with .NET
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Demo—delegates and events
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Fundamental Rule #1:
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Delegate syntax:
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“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 
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
Practical Development with .NET
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Demo—how to screw up Boxing/Unboxing
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How is .NET so FAST?
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Value Types vs. Reference Types
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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 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
QUESTIONS???
Thank you all Very Much!
Michael [email protected]
Chris [email protected]
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