SWL004

VS.NET and C#Tips and Tricks

Juval Löwy

www.idesign.net

About Juval LöwySoftware architect

Consults and trains on .NET migration and design

MS Regional Director for the Silicon Valley

AuthoredProgramming .NET components (2003, O’Reilly)

COM and .NET component services (2001, O’Reilly)

Participates in the .NET design reviews

Contributing editor and columnist to the Visual Studio Magazine

Contact at www.idesign.net

WinCV

Header-file-like type information"C:\Program Files\Microsoft Visual Studio .NET 2003\SDK\v1.1\Bin\WinCV.exe"

WinCV

.NET Best-kept secret

Intelisense on steroidsBase types

Other methods

Quick referenceSaves sifting through MSDN

Can customize assembly listWinCV.exe.config

Large project life saver

Linked FilesLinked mode for opening a file

References the file for compilation purpose, but does not copy it

Example: SolutionInfo.cs file, sharing:snk file

Version

Security policy

Copyrights

Company name

Multiple Projects StartupCan launch multiple applications from the same solution

Same debug session with F5 (Start button )

Solution|Properties|Startup Project

Blank Solution

Often, solution contains multiple projects

Solution file should not be part of any specific project

The result of adding projects to existing project

Create a blank solutionFile|New|Blank solution…

Add projects to it

Can also use Empty Project as template for content and structure

Task List

Machine-generated entriesCompilation errors

Click to source

//TODO in the code adds a task

Build EventsAdd pre/post build action

C# .NET 1.1 only

Example- Registering in the GAC after successful build

Build Events

Can use marcos

Treat Warnings as Errors Project Properties|Configuration Properties|Build

Make sure level 4 warning level is set

A must for release buildPreferable debug as well

Drag-and-Drop Elements

Windows Form, Web Form, Web Services can accept drag-n-drop

SQL tableGenerates adaptor, connection, command, dataset

Components Event log, directory watcher, timer, etc

Drag-and-Drop Elements

To add ability to mere classes, derive from Component

System.ComponentModel

Can remove derivation later on

VS.NET displays component icon

using System.ComponentModel;

namespace MyClassLibrary

{

public class MyClass : Component

{…}

}

Rectangular Selection

Press ALT while dragging cursor to mark section

Very useful in removing namespaces and repeated definitions

Document Outline

Hierarchy navigation ASP.NET forms, HTML, XML

Helpful in complex files View|Other Windows|Document Outline

C# Event AccessorsInstead of raw event member, use add/remove accessors

Like properties

Promote encapsulation and loose couplingpublic delegate void MyDelegate(int num); public class MySource{ protected event MyDelegate m_NumberChangedEvent; public event MyDelegate NumberChangedEvent { add { m_NumberChangedEvent += value; } remove { m_NumberChangedEvent -= value; } }}

C# Event Accessors

Subscriber uses “normal” event syntax:

public class MySink{ public void OnNumberChanged(int num) { MessageBox.Show(num.ToString()); }}

MySource source = new MySource();MySink sink = new MySink();

source.NumberChangedEvent += new MyDelegate(sink.OnNumberChanged);

Context-Bound ObjectApp domains are subdivided into contexts

Process A

AppDomain A

Context 1

Context 2

Process B

AppDomain B

Context 3

Context 4

AppDomain C

Context 5

Executes in exactly one contextFixed for life

Any class derived from ContextBoundObject

Context bound is also marshaled by ref

ContextBoundObject derives from

MarshalByRefObject

All calls intercepted

Context-Bound Object

public class MyClass : ContextBoundObject{…}

Example - Synchronization

.NET associates object with a shared lock

.NET intercepts calls coming into the contextTries to acquire lock (blocks if owned by another thread)

Unlocks lock on the way out of context

Pending callers queued

using System.Runtime.Remoting.Contexts;

[Synchronization]public class MyClass : ContextBoundObject{ public MyClass(){} public void DoSomething(){} //other methods and data members }

Interception Architecture

Context-bound object always accessed via proxy

App Domain

Context 1

Client

Context 2

Proxy(interception)

ContextBoundObject

Interception Architecture

TransparentProxy

Client

MethodCall()

RealProxy

ContextBoundObject

Message Sink A

Sink B Message

Sink B

StackBuilder

SinkMessage

MethodCall()

The Logbook Service

MotivationMethod call tracing and error logging are crucial to robust and faster development time

In distributed environment flight recorder is worth its weight in gold

By examining log entries, you analyze what took place, across machines and applications, and the source of the problem is almost immediately evident

Useful in post deployment, to troubleshoot customer problems

The Logbook Service

What is loggedLocation: machine, app domain name, thread (ID and name), context ID

Caller’s identity (user name)

Target object : assembly, type, member being accesses

Date and time

Exception type and message

The Logbook Service

Using the logbook

Can specify filter:

using ContextLogger; [Logbook]public class MyClass : ContextBoundObject{…}

public enum LogOption{ MethodCalls,//Default Errors} [Logbook(LogOption.Errors)]public class MyClass : ContextBoundObject{…}

The Logbook Architecture

Proxyand

InterceptionClient

[Logbook]

ContextBoundObject

LogSink

Database

LogbookSingleton

Logbook Viewer

Loosely Coupled Events

Effective way of de-coupling components

Other capabilities such as security, queuing, transactions

With delegate-based events:Client has to subscribe per event per publisher

Coupled life line

Cannot subscribe to type

No administrative setting of connection

LCE lets you configure subscriptions

LCE has separate life line

Can subscribe existing objects as well

Loosely Coupled Events

Deliver the event to .NET, not the subscribers

PersistentSubscriber

ISink

Component(publisher)

.NETEnterpriseServices

Component persistent subscription list

TransientSubscriber

ISink

Register Transient Subscription

Fire eventFires event

2

Please Publish3

Create

5

Fire event6

7

Look for a subscription4

ISink

Create1

Event Class

Loosely Coupled Events

EventClassAttribute denotes a managed class as an event class

public interface IMySink{ void OnEvent1(); void OnEvent2();}

[EventClass]public class MyEventClass : ServicedComponent,IMySink{ public void OnEvent1() {} public void OnEvent2() {}}

Publishing event

Can fire in parallel

IMySink sink;sink = new MyEventClass();sink.OnEvent1();

[EventClass(FireInParallel = true)]public class MyEventClass : ServicedComponent{ public void OnEvent1() {} public void OnEvent2() {}}

Loosely Coupled Events

Loosely Coupled Events

Persistent subscribersGet created to handle event

Admin support

Persist machine reboot

Transient subscribersNotifying existing subscribers

Gone after machine reboot

No out-of-the-box supportUse my helper class

No admin support

Conditional Compilation

Exclude method call from compilationWhen the condition is not defined

System.Diagnostics

#define MySpecialCondition //usually DEBUGpublic class MyClass{ public MyClass() {} [Conditional("MySpecialCondition")] public void MyMethod() {}}//Client side codeMyClass obj = new MyClass();//This line is conditionalobj.MyMethod(); 

Killing a Thread

Do not call Abort()Thread may need to do clean-up

Abort() does not allow graceful exit

Abort() is not guaranteed to workThread can do indefinite processing in catch{}

ResetAbort(), suspended, interop calls

The thread method should check a flagProtect flag with a lock

Kill() method should set flag and wait for thread to terminate

public class WorkerThread : IDisposable{ protected Thread m_ThreadObj; protected bool m_EndLoop; protected Mutex m_EndLoopMutex; protected bool EndLoop { set { m_EndLoopMutex.WaitOne(); m_EndLoop = value; m_EndLoopMutex.ReleaseMutex(); } get { bool result = false; m_EndLoopMutex.WaitOne(); result = m_EndLoop; m_EndLoopMutex.ReleaseMutex(); return result; } } public WorkerThread() { m_EndLoop = false; m_ThreadObj = null; m_EndLoopMutex = new Mutex(); }

public class WorkerThread : IDisposable{ public void Start() { m_ThreadObj = Thread.CurrentThread; int i = 0; while(EndLoop == false) { //do work here } }

//Kill is called on client thread - must use cached thread object public void Kill() { Debug.Assert(m_ThreadObj != null); if(m_ThreadObj.IsAlive == false) return; EndLoop = true; //Wait for thread to die m_ThreadObj.Join();

if(m_EndLoopMutex != null) m_EndLoopMutex.Close(); } //Rest of WorkerThread

Thread HandleThread Handle

ThreadThread does not provide a does not provide a WaitHandleWaitHandleUnlike Windows Unlike Windows

Join()Join() is not good enough is not good enough Cannot combine in multiple wait operationCannot combine in multiple wait operation

No atomic wait No atomic wait

Have the wrapper class expose a event Have the wrapper class expose a event handle handle

Signaled when the thread method exists Signaled when the thread method exists In In finallyfinally statement statement

public class WorkerThread { protected ManualResetEvent m_ThreadHandle; public WorkerThread() { m_ThreadHandle = new ManualResetEvent(false); //More initialization } public WaitHandle Handle { get { return m_ThreadHandle; } } private void Run() { try { //Do work here } finally { m_ThreadHandle.Set(); } } //Rest of the implementation }

More at TechEd

C# Best Practices DEV312

Distributed Security PracticesDEV354

Building High-Performance Applications with Visual Studio .NET

DEV326

Application and Library VersioningDEV343

Software Legends – VS.NET and C# tips and tricksSWL004

ResourcesResourcesProgramming .NET components

By Juval Lowy, O'Reilly April 2003

www.idesign.net

.NET Master Class3-4 annually

Upcoming events onwww.idesign.net

Community Resources

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SOFTWARE LEGENDSOFTWARE LEGENDJuval LowyJuval Lowy

THURSDAY 3rd JULY at 16.15-16.45 hrs

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© 2003 Microsoft Corporation. All rights reserved.© 2003 Microsoft Corporation. All rights reserved.This presentation is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS OR IMPLIED, IN THIS SUMMARY.This presentation is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS OR IMPLIED, IN THIS SUMMARY.