Bill Campbell, UMB Microsoft's.NET C# and The Common Language Runtime.

Bill Campbell, UMBBill Campbell, UMB

Microsoft's .NETMicrosoft's .NET

C# and C# and

The Common Language The Common Language Runtime Runtime


CorrespondenceCorrespondence

Java (J2EE)Java (J2EE) .Net.Net

Family of StandardsFamily of Standards Family of Products Family of Products

Cross platformCross platform WindowsWindows

JavaJavaC# (VB, C++, Jscript)C# (VB, C++, Jscript)

& others& others

JSPJSP ASP+ASP+


Correspondence (cont)Correspondence (cont)

Java (J2EE)Java (J2EE) .Net.Net

JDBCJDBC .ADO.ADO

EJBEJB DCOM+DCOM+

IIOP, SOAP (xml)IIOP, SOAP (xml) Remoting, SOAPRemoting, SOAP

Several VendorsSeveral Vendors One vendorOne vendor


C# a language for programmersC# a language for programmers

From C and C++ From C and C++ Managed Data (garbage collection)Managed Data (garbage collection) Larger than Java Larger than Java

• (80 vs 50 keywords)(80 vs 50 keywords)• Preprocessing directives, #ifdef etc.Preprocessing directives, #ifdef etc.• Operator overloadingOperator overloading• Syntactic sugar (convenience)Syntactic sugar (convenience)


Everybody's an ObjectEverybody's an Object

Type

Value Type Ref Type

Scalar Enumeration Class Interface

Structure

(stack allocated) (heap allocated)

Delegate


Choice in ScalarsChoice in Scalars

sbytesbyte floatfloat charcharbytebyte doubledouble boolboolshortshort decimaldecimalushortushortintintuintuintlonglongulongulong


Scalars are structsScalars are structs

int is really syntax for Int32int is really syntax for Int32

struct Int32struct Int32{...{...}}

so, e.g. 56.ToString()so, e.g. 56.ToString()


keywordskeywordsabstract as base bool breakabstract as base bool breakbyte byte case case catch char catch char checked checked class const continue decimal defaultclass const continue decimal defaultdelegate do double else enumdelegate do double else enumevent explicit extern false finalevent explicit extern false finalfixed float for foreach goto fixed float for foreach goto if implicit in int interfaceif implicit in int interfaceinternal is lock long namespace internal is lock long namespace new null object operator out new null object operator out override params private protected public override params private protected public readonly ref return sbyte sealed readonly ref return sbyte sealed short sizeof stackalloc static string short sizeof stackalloc static string struct switch this throw true struct switch this throw true try typeof uint ulong unchecked try typeof uint ulong unchecked void volatile whilevoid volatile while


foreachforeach

foreach (int elem in intArray) foreach (int elem in intArray) {{

……}}

foreach (BankAccount acct in accounts) foreach (BankAccount acct in accounts) {{

……

}}


Properties mimic field syntaxProperties mimic field syntax

Temperature t = New Temperature(...);Temperature t = New Temperature(...);

......

double c = t.DegreesCelsius;double c = t.DegreesCelsius;

......

t.DegreesCelsius = 0.0;t.DegreesCelsius = 0.0;

double f = t.DegreesFarenheit; // 32.0double f = t.DegreesFarenheit; // 32.0


Behave like getters and settersBehave like getters and setters

public double DegreesCelsiuspublic double DegreesCelsius

{{

getget

{{

return degreesCelsius;return degreesCelsius;

}}

setset

{{

degreesCelsius = value;degreesCelsius = value;

}}

}}


DegreesFahrenheit PropertyDegreesFahrenheit Property

public double DegreesFahrenheitpublic double DegreesFahrenheit{{

getget{ {

return 9.0/5.0*DegreesCelsius + 32.0;return 9.0/5.0*DegreesCelsius + 32.0;}}setset{{

DegreesCelsius = 5.0/9.0*(value-32.0);DegreesCelsius = 5.0/9.0*(value-32.0);}}

}}


IndexersIndexers

public class BitSetpublic class BitSet{{ ulong word;ulong word; public bool this[int position]public bool this[int position] {{

getget{ { if (position < 0 || position > 63)if (position < 0 || position > 63)

throw new IndexOutOfRangeException();throw new IndexOutOfRangeException(); elseelse

return word & (1 << position) != 0;return word & (1 << position) != 0;}}......

}}


Properties and Indexers Properties and Indexers Ubiquitous Ubiquitous

button.Sizebutton.Size

"cat".length => 3"cat".length => 3"cat"[1] => 'a'"cat"[1] => 'a'

hashtable["key"] = "value";hashtable["key"] = "value";......hashtable["key"] => "value"hashtable["key"] => "value"


Boxing and Unboxing Boxing and Unboxing

Like Java, Collections of (Reference) ObjectsLike Java, Collections of (Reference) Objects

hashtable["one"] = (object) 1; // 1 boxedhashtable["one"] = (object) 1; // 1 boxed

int one = (int) hashtable["one"]; // unboxedint one = (int) hashtable["one"]; // unboxed


Delegates and Events Delegates and Events

Type safe callbacksType safe callbacks

Button button = new Button("Press Me");Button button = new Button("Press Me");button.Click += new button.Click += new

System.EventHandler(button_Click);System.EventHandler(button_Click);......private void button_Click(object sender, private void button_Click(object sender,

System.EventArgs e)System.EventArgs e){{ <do whatever you want for a pressed button><do whatever you want for a pressed button>}}


Attributes Attributes For marking up your programFor marking up your program

[Serializable][Serializable]class BankAccountclass BankAccount{ ...{ ...}}

[Flags, Serializable][Flags, Serializable] You can define your ownYou can define your ownpublic enum FileAttributespublic enum FileAttributes{{ They can have argumentsThey can have arguments ReadOnly = 0x0001,ReadOnly = 0x0001, ...... Your program can actYour program can act Encrypted = 0x4000Encrypted = 0x4000 upon them at run time upon them at run time}}


Common Language Runtime (CLR)Common Language Runtime (CLR)

Visual BasicVisual Basic C++C++ JScriptJScript CLR (JIT) CLR (JIT) native native

codecode C#C# (others) (others) CLR CLR a modela model


Common Type SystemCommon Type System

Your language can talk to all the Your language can talk to all the others so long as it supports:others so long as it supports:

boolbool short short ulongulong

charchar intint

floatfloat longlong

doubledouble bytebyte


CLR EntitiesCLR Entities

Assemblies are logical collections of Assemblies are logical collections of program parts (classes, interfaces, etc.)program parts (classes, interfaces, etc.)• Contain ALL the metadata required for an Contain ALL the metadata required for an

application (so it doesn't have to go in application (so it doesn't have to go in registries)registries)

• One assembly can be physically captured by One assembly can be physically captured by several (.exe or .dll) files several (.exe or .dll) files

• Support versioningSupport versioning• Can operate under one of several publishing Can operate under one of several publishing

policies (eg bug fixes vs. new versions)policies (eg bug fixes vs. new versions) Namespaces are purely logicalNamespaces are purely logical


CLR ImplementationCLR Implementation

CLR has a real assembly languageCLR has a real assembly language

assembly P -ildasmassembly P -ildasm -ilasm -ilasm P P

CLR is a beautiful target for compilersCLR is a beautiful target for compilers

Implemented using a "just in time" Implemented using a "just in time" compilercompiler

Generational garbage collectorGenerational garbage collector


How to learn about this stuffHow to learn about this stuff

InternetInternet Good books (Microsoft Press)Good books (Microsoft Press) Download the MS Framework SDKDownload the MS Framework SDK Borrow Visual Studio .net under the Borrow Visual Studio .net under the

msdnaa program here at umb (You must msdnaa program here at umb (You must be a student and adhere to the licensing be a student and adhere to the licensing agreement.)agreement.)

Take one of my summer courses: CS650 or Take one of my summer courses: CS650 or CS697a (both limited in size)CS697a (both limited in size)

Bill Campbell, UMB Microsoft's.NET C# and The Common Language Runtime.

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