.NET Framework Library

1
.NET Framework Library

• A language independent universe of classes and
  components for your applications

2
Objectives

• Provide an overview about various aspects of the
  .NET framework libraries not covered elsewhere in
  the Microsoft .NET Developer Tools Readiness Kit

3
Contents

• Section 1 Introduction
• Section 2 The System Namespace
• Section 3 Collection Classes
• Section 4 I/O and Networking
• Section 5 Process Management
• Section 6 Miscelleaneous Services
• Summary

4
Section 1 Introduction

• Looking Back
• The Microsoft .NET Framework Library

5
Looking Back

• Language Dependent Runtime Libraries
• C-Runtime library
• C Standard Template Library
• Visual Basic Runtime
• API holes plugged with ActiveX controls
• Discriminatory access to functionality
• Many APIs unsupported by Visual Basic
• Advanced tasks often require C/C
• Core functionality scattered all over Windows
• ActiveX controls, System DLLs, SDKs, IE

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The .NET Framework Library

• One-stop, well-organized class framework
• OS-independent subset submitted to ECMA
• Standardization backed by Microsoft, HP, Intel
• Subset includes most things covered here
• http//msdn.microsoft.com/net/ecma
• Integrates all current Windows technologies
• Everything in one place for all languages
• Windows Forms, GDI, Printing for Windows Dev
• Web Forms, Web Services, Networking for Net Dev
• Supports Active Directory, WMI, MSMQ, Services

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Section 2 The System Namespace

• System.Object
• The not-so-primitive "primitive" types
• String and text classes
• Dates, times and calendars
• System console support

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The Root of Everything .NET Object

• Base class for each and every type
• Inheritance from System.Object is typically
  implicit
• All simple and complex types share the same base
• Single base-class makes framework consistent
• Collection classes can be used for everything
• Intrinsic model for handling variant types
• Strongly typed. No pointers, no structures
• Much less error prone than COM's VARIANT type
• System.Object is a reference type
• Value types (internally) inherit from ValueType
• Special class derived from Object

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System.Object's Methods 1/2

• bool System.Object.Equals(Object o)
• Reference identity for reference types (default)
• Overridden for value types to test value identity
• void System.Object.Finalize()
• To be overridden by subclasses
• Called when object is garbage collected
• int System.Object.GetHashCode()
• i.e. used with System.Collections.HashTable
• Should be overriden to return good hashes
• Good hash distribution speeds up hash tables
• Default implementation Identity-based hash

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System.Object's Methods 2/2

• System.Type System.Object.GetType()
• Retrieves the type object for the object's class
• GetType() is the entry point for .NET Reflection
• System.Object System.Object.MemberwiseClone()
• Creates a exact clone of "this" object
• Works through Reflection with any class
• System.String ToString()
• To be overriden Returns text representation
• Default returns qualified name of "this" class
• Not designed for user messages (use IFormattable)

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The "Primitive" Types

• Traditionally perceived as "magic" or "special"
• There is no primitive-type magic-ness in .NET!
• Very SmallTalk-like model
• "Primitive" types are regular framework types
• However, still exposed as language-intrinsic
  types
• C bool, int, long, string, double, float
• Visual Basic.NET Boolean, Integer, String
• "Primitives" are mostly value-types
• Exception System.String is reference type
• "Primitive" Types are not so primitive anymore
• Full featured classes, rich functionality

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Integer Numerics

• System.Int16, System.Int32, System.Int64
• Standard integer (whole number) types
• 16,32 and 64 bit wide. Highest bit is sign
• Int32 is typically default language-mapped
  Integer
• Implemented framework interfaces
• IFormattable locale specific text formatting
• IConvertible standard conversion into other core
  types
• IComparable standard value-comparison with other
  objects
• Parse() method provides rich from-text
  conversions
• System.UInt16, System.UInt32, System.UInt64
• Unsigned equivalents

13
Floating Point Numerics 1/3

• System.Single, System.Double
• IEEE 754 floating point numbers
• As used in most common programming languages
• Values internally represented as fractions
  (narrowed values)
• Good for scientific/technical use, not for
  business numerals
• System.Single single precision, 32-bit
• System.Double double precision, 64-bit
• IFormattable, IComparable, IConvertible

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Floating Point Numerics 2/3

• System.Decimal
• 128 bit, 28 significant and precise digits
• Good for business numerals, monetary amounts
• IFormattable, IComparable, IConvertible
• System.Double, System.Single specials
• Support positive and negative infinity
• PositiveInfinity and NegativeInfinity constants
  on class
• Can represent not-a-number (NaN) values
• NaN constant on class. NaN always compares false

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Floating Point Numerics 3/3

• System.Decimal specials
• Static value manipulation methods
• Abs(d), Negate(d) Positive/Negative sign
• Truncate(d), Floor(d), Round(d,n) Fractional
  part
• Static arithmetic methods
• Add(d,d), Multiply(d,d), Subtract(d,d),Divide(d,d)
  ,Mod(d,d)
• All equivalent operators are defined for the
  class

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Doing Numerics System.Math

• System.Math class mainly supports IEEE types
• Some operations for all numerics
• Abs(), Log(), Max(), Min(), Round(), Sign()
• Operations
• Trigonometry Sin(),Cos(), Tan(), Acos(), Asin()
• Powers and Logarithms Pow(), Log(), Sqrt()
• Extremes Min(), Max()
• Rouning Floor(), Ceil(), Rint(), Round()

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System.String

• System.String is the cross-language string
• One storage method, one API, unified handling
• Locale-aware, always Unicode
• Fully-featured string handling capabilities
• Forward and reverse substring searches
• IndexOf(), LastIndexOf(), StartsWith(),
  EndsWith()
• Whitespace stripping and padding
• Trim(), PadLeft(), PadRight()
• Range manipulation and extraction
• Insert(), Remove(), Replace(), Substring(),
  Join(), Split()
• Character casing and advanced formatting
• ToLower(), ToUpper() and
• Format() much like C's printf but safe

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More Strings System.Text Namespace

• StringBuilder
• Super-efficient for assembling large strings
• Encoders and Decoders
• Support character encoding and conversions
• ASCII, UTF-8, UTF-7, Windows Codepages
• Unicode encoder for full UTF-16 compliant streams
• Encoder can write and decoder detect byte-order
  marks
• Supports big-endian and little-endian Unicode
  encoding

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Other Core Types

• System.Byte, System.SByte Single byte numeric
• System.Char Single Unicode character
• System.Boolean True or False logical value
• System.Guid
• 128-bit, universally unique identifier
• Built-in generator System.Guid.NewGuid()
• Intrinsic conversions from and to strings
• The "Nothings"
• System.DBNull database-equivalent NULL type
• System.Empty like COM's VT_EMPTY
• System.Missing used with optional args

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Date and Time Support

• System.DateTime class for dates and times
• Virtually unlimited date values (100 AD to 9999
  AD)
• Date and Time arithmetics built-in
• AddDays(), AddSeconds()
• Sophisticated, locale-aware formatting and
  parsing
• System.TimeSpan for durations
• Can represent arbitrary timespans
• Can express span in arbitary units by conversion
• System.TimeZone for time-zone support

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Date and Time to the Max

• System.Globalization.Calendar namespace
• Correct date expressions based on local calendars
• GregorianCalendar standard western calendar
• JulianCalendar
• HebrewCalendar
• JapaneseCalendar
• KoreanCalendar
• ThaiBuddhistCalendar
• HijriCalendar
• Two-way 2/4 digit-year windowed conversion

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The Console

• System.Console class for console I/O
• Supports standard in, standard out, standard
  error
• Writing to the console
• Write() or WriteLine()
• Supports String.Format syntax
• Console.Write("Snowwhite and the 0 dwarfs", 7)
• Reading from the console
• Read() reads on characters
• ReadLine() reads one full line

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Other System Goodies

• System.URI class
• Two-way parsing and construction of URIs
• System.Random class
• Random number generator
• System.Radix class
• Numeric base-system conversions (eg. Dec/Hex)
• System.Convert class
• One-stop place for core type conversions

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Section 3 Collection Classes

• Arrays
• Collection Interfaces
• The Collection Classes

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The Array

• Only collection outside Collections namespace
• System.Array class
• Mapped to language-intrinsic arrays
• Polymorphic, stores System.Object elements
• Arbitrary number of dimensions, lengths
• Specified at creation time (CreateInstance)
• After construction, array dimensions are fixed
• Supports sorting
• Self-comparing IComparable objects
• External comparisons with IComparer
• Supports binary searches on sorted arrays

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Collection Interfaces 1/2

• IEnumerable
• Implements enumerable value set
• GetEnumerator() returns IEnumerator iterator
• IEnumerator Current, MoveNext(), Reset()
• ICollection (inherits IEnumerable)
• Basic collection interface Count(), CopyTo()

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Collection Interfaces 2/2

• IDictionary (inherits ICollection)
• Basic association container interface
• Keys / Values table implementation
• Add(), Remove(), Contains() and Clear() methods
• IList (inherits ICollection)
• Basic list container interface
• Add(), Remove(), Contains() and Clear() methods

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Collection Classes 1/3

• System.Collections.ArrayList / ObjectList
• Dynamic arrays implementing IList
• Can grow and shrink in size (unlike System.Array)
• System.Collections.BitArray
• Super-compact array of bits
• System.Collections.HashTable
• Fast hash-table implementing IDictionary
• There is no Dictionary class. Use HashTable
• System.Collections.SortedList
• Auto-sorted, string-indexed collection

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Collection Classes 2/3

• System.Collections.Stack
• Stack implementation with Push() and Pop()
• Still, fully enumerable (IEnumerable)
• System.Collections.Queue
• Queue with Dequeue() and Enqueue()
• Fully enumerable

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Collection Classes 3/3

• System.NameObjectCollectionBase
• Abstract class, indexed view on Hashtable
• Combines indexed order with Hashtable-speed
• Base for quite a few subsystem collections
• System.NameValueCollection
• Comma separated string lists for same key entries

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Section 4 I/O and Networking

• Directories and Files
• Streams, Stream Readers and Stream Writers
• Isolated Storage
• Networking Support

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Directories and Files

• Fully object-oriented way to explore the file
  system
• System.IO.Directory represents a directory
• GetDirectories(mask) gets subdirectories
• GetFiles(mask) gets contained files
• System.IO.File represents a file
• Can construct directly by providing a path
• Or returned from GetFiles() enumeration
• Unifies file system entries and stream access!
• All Open...() methods return System.IO.Stream
• Open(), OpenRead(), OpenWrite(), OpenText()

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Streams

• Abstract base-stream System.IO.Stream
• Read(), Write() for basic synchronous access
• Full asynchronous support
• Call BeginRead() or BeginWrite() and pass
  callback
• Callback is invoked as soon as data is received.
• Asynchronous call completed with
  EndRead()/EndWrite()
• System.IO.FileStream
• Can open and access files directly
• Actual type returned by File.Open()
• System.IO.MemoryStream
• Constructs a stream in-memory

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Stream Readers 1/2

• Higher-Level access to Stream reading functions
• System.IO.BinaryReader
• Designed for typed access to stream contents
• Read methods for most core data types
• ReadInt16(), ReadBoolean(), ReadDouble(), etc.
• System.IO.TextReader
• Abstract base class for reading strings from
  streams

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Stream Readers 2/2

• System.IO.StreamReader (implements TextReader)
• ReadLine() reads to newline
• ReadToEnd() reads full stream into string
• System.IO.StringReader (implements TextReader)
• Simulates stream input from string

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Stream Writers

• High-level access to Stream writing functions
• System.IO.BinaryWriter
• Designed for typed writes to streams
• gt15 strongly typed overloads for Write() method
• System.IO.TextWriter
• Abstract base class for writing strings to
  streams
• Includes placeholder-formatted strings
• System.IO.StreamWriter (implements TextWriter)
• Writes strings to streams with encoding support
• System.IO.StringWriter
• Simulates streams-writes on an output string

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Isolated Storage

• Scoped, isolated virtual file system
• Scoped to User, Assembly or Application Domain
• Great as temporary storage location
• Sandboxed environment
• Storage location managed by runtime system
• System.IO.IsolatedStorage.IsolatedStorageFile
• Container for virtual file system
• Static methods for access/creation of storages
• ... IsolatedStorageFileStream
• Stream implementation on isolated storage
• Behaves like any ordinary file

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The Net in .NET System.Net

• System.Net contains all network protocol support
• Low-level support for IP sockets and IPX
• Application level protocol implementations (HTTP)
• Authentication methods for HTTP
• Basic, Digest, NTLM Challenge/Reponse
• Full cookie support for HTTP

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Request and Response Classes

• System.Net.WebRequest class
• Base class for network request/response protocols
• Abstract base for HttpWebRequest
• Create requests through WebRequest.Create()
• Plug in new protocol handlers with
  RegisterPrefix()
• System.Net natively supports HTTP and HTTPS
• Request can be populated through stream
• WebRequest.GetRequestStream()
• Request is executed on GetResponse()
• Data through WebResponse.GetReponseStream()

40
Protocol Support Classes

• Manage connectivity through ServicePoint
• Connections managed by ServicePointManager
• Per-Endpoint configuration of connection params
• System.Net.EndPoint information in ServicePoint
• Base class for endpoints
• System.Net.IPEndPoint
• Represents an IP endpoint with IPAdress and port
• System.Net.IpxEndPoint
• Represents an IPX endpoint
• System.Net.DNS
• Access to DNS nameservers and name resolution

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IP Sockets

• System.Net.Sockets.Socket for raw sockets
• send with Send(), receive with Receive()
• Socket.Connect() connects to EndPoint
• Supports TCP, UDP, IP Multicast, IPX and others
• Socket.Bind() and Socket.Listen() create listener
• High-Level wrappers for TCP, UDP
• TcpClient, UdpClient provide NetworkStream
• Usable with System.IO's stream readers/writers
• TcpListener implements TCP listener
• Can pickup connection requests as Socket or
  TcpClient

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Section 5 Process Management

• Process control
• Threading support

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Processes

• System.Diagnostics.Process class
• Allows creating/monitoring other processes
• Monitoring All Task-Manager stats accessible
• Process.Start() equivalent to Win32 ShellExecute
• Arguments are set via ProcessStartInfo class
• Supports shell verbs (print,open)
• Supports waiting for termination (WaitForExit)
• Can register event handlers for "Exited" event
• Explicit termination supported in two ways
• Rambo method Kill()
• Nice-guy method CloseMainWindow()

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System.Threading.Thread

• Every .NET application is fully multi-threaded
• No more haggling with threading models
• Except in COM/Interop scenarios, of course
• Trade-Off Must take care of synchronization
• System.Thread represents a system thread
• Threads are launched with entry point delegate
• Object-oriented threading model
• No arguments passed to entry point
• Thread launch-state is set on object hosting the
  delegate
• ThreadPool implicitly created for each process

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Creating Threads

• // instantiate class that will execute on
  threadPulsar pulsar new Pulsar()// create
  delegate for entry point on instance
• ThreadStart threadStart new
  ThreadStart(pulsar.Run)// create new thread
  object and start the threadThread thread
  new Thread(threadStart)
• thread.Start()
• // do other things ...// wait for thread to
  complete
• thread.Join()

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Thread Synchronization Monitor

• System.Threading.Monitor class
• Supports Wait/Pulse coordination model
• One thread enters Wait()
• Other thread calls Pulse() to release Wait() lock
• Similar to Win32 critical sections model
• Can synchronize on every managed object

// enter critical section or waitMonitor.Enter(th
is)// perform guarded action internalState
SomeAction( )// release lock Monitor.Exit(this)
// C intrinsic equivalentlock (this)
internalState SomeAction( )
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More Threading

• Synchronization with WaitHandle
• Mutex Single synchronization point
• Mutex.WaitOne() waits for Mutex to be available
• Mutex.ReleaseMutex() releases mutex lock
• AutoResetEvent, ManualResetEvent
• .WaitOne() waits for event to be signaled
• Set() sets event, Reset() resets event state
• Static WaitAny() / WaitAll() for multiple waits
• Threading Timers for timed callbacks
• Interlocked class for lightweight locking
• Interlocked.Increment( ref i )

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Section 6 Advanced Services

• Windows 2000 Services
• Diagnostics and Profiling

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Windows 2000 Services

• System.Management
• Windows Management Instrumentation (WMI)
• System.Messaging
• Microsoft Message Queue
• System.DirectoryServices
• Active Directory Services
• System.ServiceProcess
• Expose .NET applications as Windows Services

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Windows 2000 Event Log

• System.Diagnostics.EventLog class
• Reading event logs
• Static EventLog.GetEventLogs() gets all machine
  logs
• EventLog.Log indicates the type of event log
• Application, System, Security, etc.
• EventLog.Entries retrieves all entries for a log
• EventLog.EventLogEntryCollection
• Contains EventLogEntry elements
• Can register event handler to monitor log
  continuously
• Writing event logs
• Create new source with CreateEventSource()
• Write to log with WriteEntry()

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Other Diagnostic Services

• System.Diagnostics.PerformanceCounter
• Access and create performance counters
• System.Diagnostics.StackTrace
• Creates call stack traces programmatically
• System.Diagnostics.Trace
• Allows code instrumentation with diagnostic
  output
• Register listeners to receive trace events
• Visual Studio.NET automatically registers
  listeners
• Trace code can be conditionally disabled
• No code is not generated, although calls remain

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Summary

• Everthing is based on System.Object
• Rich set of foundation classes
• Comprehensive set of general-purpose,
  object-oriented classes for Networking and I/O
• Great access to Windows 2000 services
• Rich diagnostic and monitoring facilities

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Questions?