An Overview of Microsoft .NET Framework 3.0

Introduction

I have been come across many people thinking that WinFx is not related to .NET Framework. The funniest answer I have gotten is that it is a fix related to Windows PC protection similar to WinFix. It is good decision from Microsoft for changing its name from .NET Framework 3.0. This article gives a clear explanation about the additional technologies/features that are included in .NET Framework 3.0, namely Windows Presentation Foundation (WPF), Windows Workflow Foundation (WF), Windows Communication Foundation (WCF) and Windows Card Space (WCS).

What Happens when we install Framework 3.0

Does it install new version of the Framework? No. It is just an upgraded Framework from 2.0 that comes along with WPF (Avalon), WCF (Indigo), WCS (InfoCard) and WF. It is a Framework that sits on the top of the 2.0 Framework along with Common Language Runtime (CLR) and BCL (Base Class Library). Framework 3.0 comes with CLR version 2.0. We are still using version 2.0 compilers for the Framework 3.0. So if we have Framework 2.0 installed in our system, it will install managed API's that are required for workflow, presentation, communication, etc. If Framework 2.0 is not installed, it will install Framework 2.0 and then install all other upgraded required components. The serious question that comes to mind is "why the version number is changed if we are still using 2.0 compliers." The reason for choosing the new version number is Avalon, Indigo, Workflow, and Info card are all major new pieces of platform technology.

Windows Presentation Foundation (WPF)

This is formerly known as the code named "Avalon," a graphical feature in Framework 3.0 that makes easy to build next generation web applications with the help of rich User Interface (UI), documents and media. This is used to display more advanced graphics that helps a developer to improve his/her designing skills using programming skills, which would be quite challenging. We developers can produce outstanding user interfaces using multimedia and document services in WPF. We can also make use of vector graphics, user interface, 2D and 3D drawing, fixed and adaptive documents, typography, raster graphics, animation, data binding, audio, video and develop graphic/animation through declarative programming. WPF allows developers as well as designers to collaborate and develop awesome visual user interfaces. Here are the two different developer environments that are used to make developer and designer work together.
1. Microsoft Visual Studio
2. Microsoft Expression Interactive Designer

The language that is used to develop application user interfaces in WPF is called XAML (Extensible Application Markup Language). XAML is based on XML (Extensible Markup Language). Separation of model and view is possible in XAML by placing design related information in FileName.xaml file and business logic is placed in FileName.xaml.cs file.

Core Components

The major components of WPF are:
1. Presentation Framework
2. Presentation Core
3. MILCore (Media Integration Layer)
4. DirectX

Presentation Framework and Presentation core are written in managed code. The DirectX engine is responsible for displaying. MILCore is written in unmanaged code in order to enable tight integration with DirectX. MILCore (MILCore.dll) also consists of a composition engine which is responsible for performance reasons.

Microsoft Silverlight

WPF comes with its subset Microsoft Silverlight formerly named as Windows Presentation Foundation Everywhere (WPF/E) and is a subset of WPF which depends on XAML and JavaScript. Silverlight is a cross-browser, cross-platform plug-in for delivering the next generation of .NET based media experiences for the Web and mobile applications. Silverlight offers a flexible programming model that supports AJAX, VB, C#, Python, and Ruby, and integrates with existing Web applications. It is lightweight, just 1 MB download and pretty fast. We can play many videos simultaneously without stuttering or dropping frames. No doubt WPF is next-generation graphics API. More explanation on Silverlight is out of the scope of this article. For more details on Silverlight, visit http://www.microsoft.com/silverlight.

Windows Workflow Foundation (WF)

"Workflow" is a declarative way of implementing result oriented business process in software. WWF is a programming model that helps in defining, building, executing, debugging and managing work flow related applications that are in sync with business processes. It consists of a Microsoft NET Framework version 3.0 namespace, an in-process workflow engine, and designers for Visual Studio 2005.

We can build as many work flow styles as we need based on the requirement.

Graphical designer and debugger are provided to implement work flow related software. We can make use of imperative code along with declarative modeling. It enables us to build workflow software that is more flexible and transparent.

Core Components
WF core components include:
1. Base Activity Library: This provides functionality for control flow, conditions, event handling, state management and invoking web service. One can build his or her own custom domain specific activities using the base activity.

2. Runtime Engine: This is responsible for Workflow execution and state management.

3. Runtime Services: This provides hosting flexibility and communication.

4. Visual Designer: It is responsible for graphical and code-based construction.

Once a workflow model is compiled, it can be executed inside any windows process including console applications, WinForms applications, Windows Services, ASP.NET Web sites, and Web services. Extensible Object Modeling Language [XOML] based on XAML is the language that is used for declaring the structure of workflow, business logic for the workflow.

In order to create workflow, activities using WWF are:

1. VS 2005 (comes by installing Visual Studio 2005 add-ins to design and program workflow)

2. SharePoint designer that permits building workflows for Share Point 2007

Windows Communication Foundation (WCF)

WCF is formerly known as the code “Indigo” is the first Unified Programming Model (UPM) for Service Oriented Applications (SOA). It is the unification of the technologies used to deliver distributed systems such as Enterprise Services, Messaging, .NET remoting, ASMX and WSE that run on the Microsoft platform. In other words, Windows Communication Foundation is an advanced technology to provide web services/remoting functionality with better features and reduces the time to develop a distributed system. It makes development interoperable with Non-MS Platform and integrates with existing products. We can build amazing services that would add more weight using WCF. WCF uses SOAP messages for communication between two processes. WCF has a set of API's for creating systems that send messages between services and clients. The same API's are used to create applications that communicate with other applications on the same system or on a system that resides in another company.

Core components

Here is a list of core components in WCF.

1. End Point: A WCF service is exposed to the world as a collection of endpoints. It is the point where messages are sent or received. It consists of Address, Binding and Contract.

• Address: End point consists of location where message can be sent/received. This is equivalent to a service address in WSDL. An example of Address components are URI, Identity & Headers.
• Binding: This is a communication mechanism that describes how messages can be sent. This represents configuration. It is made up of various binding elements like Transport protocol, such as TCP, HTTP, MSMQ, named pipes, Encoding such as text, Message Transmission Optimization Mechanism such as MTOM, binary, and security like asymmetric, symmetric and transport.
• Contract: It is a definition for a set of messages that can be sent or received (or both) at the address that describes what message can be sent. It describes the WCF contracts and their operations like One way, request/reply, duplex, and queuing.

2. Channel: A channel is a concrete implementation of a binding element. The channel is the implementation associated with that configuration.

3. Client: A program that exchanges messages with one or more endpoints using channels.

4. Service: A service is a construct that exposes one or more endpoints, with each endpoint exposing one or more service operations.

5. Behavior: A behavior is a component that controls various run-time aspects of a service, an endpoint, a particular operation, or a client.

Facts:

• WCF has rich communication capabilities.
• WCF is 25%—50% faster than ASP.NET Web Services and approximately 25% faster than .NET Remoting.
• It is secured, Confidential in keeping messages.
• Using WCF message transfer is reliable.

SharePoint Development Improves in Visual Studio 2010

The focus of the tooling is to automate tedious tasks, enhance the debugging experience, and provide a GUI surface for visually exploring deployment and feature packaging. These tools will replace the much-derided SharePoint Designer.

VS 2010 Tools for SP Quick info:

Building and Debugging
Visual Studio will be able to building and debug SharePoint projects. "F5 Just Works!"

Server Explorer Integration
SharePoint Connections will be an option in the VS Server Explorer. Standard Sharepoint artifacts will be viewable: ContentTypes, Features, Templates, Lists, Sites, Workflows, Workspaces. Direct manipulation of some artifact attributes will be supported through VS property grid integration.

Windows SharePoint Services Project (WSP) Import
This will automate the manual task of creating Windows SharePoint Services solution package files. Previously, to create a solution package file, a developer had to use the Makecab.exe console application that is included in the Microsoft Cabinet Software Development Kit (SDK). Makecab.exe requires specifying the Diamond Directive File (.ddf) that contains a list of all the files to include in the package. Much of this will be automated.

Visual Web Part Designer
A new WSYWIG designer will exist for authoring Web Parts. The designer will also load a user control as a web part for SharePoint. This seems to be a more tightly integrated version of the widely used SmartPart, which is a Web Part that allows hosting of ASP.NET User Controls in SharePoint.

Event Receiver Wizard
Adding Event Receivers and connecting them to Sources can be done visually through a wizard.

Workflow Integration
A new ASPX Workflow Initiation form for Workflow Project will be added. Workflow initiation forms will have a visual designer.

Packaging Editor
A new Packaging Explorer will exist that supports editing Packaging and structuring the SharePoint Features and WSP file.

Native Image Generator (Ngen.exe)

The Native Image Generator utility (Ngen.exe) allows you to run the JIT compiler on your assembly's MSIL and generate native machine code which is cached to disk. After the image is created .NET runtime will use the image to run the code rather than from the hard disk. Running Ngen.exe on an assembly potentially allows the assembly to load and execute faster, because it restores code and data structures from the native image cache rather than generating them dynamically.

The key points about Native Image Generator are:

• Native images load faster than MSIL because JIT compilation and type-safety verification is eliminated.

• If you are sharing code between process Ngen.exe improves the performance significantly. As Native image generated Windows PE file so a single DLL file can be shared across applications. By contrast JIT produced code are private to an assembly and can not be shared.

• Native images enable code sharing between processes.

• Native images require more storage space and more time to generate.

• Startup time performance improves lot. We can get considerable gains when applications share component assemblies because after the first application has been started the shared components are already loaded for subsequent applications. If assemblies in an application must be loaded from the hard disk, does not benefit as much from native images because the hard disk access time shadows everything.

• Assemblies in GAC do not benefit from Native image generator as the loader performs extra validation on the strong named assemblies thus shadowing the benefits of Native Image Generator.

• If any of the assemblies change then Native image should also be updated.

• You should have administrative privilege for running Ngen.exe.

• While this can fasten your application startup times as the code is statically compiled but it can be somewhat slower than the code generated dynamically by the JIT compiler. So you need to compare how the whole application performance with Ngen.exe and with out it.

SQL Cache Dependency in ASP.NET 2.0

SQL cache dependencies is a new feature in ASP.NET 2.0 which can automatically invalidate a cached data object (such as a Dataset) when the related data is modified in the database. So for instance if you have a dataset which is tied up to a database tables any changes in the database table will invalidate the cached data object which can be a dataset or a data source.

Steps to enable SQL Cache Dependency in ASP.NET 2.0

• Enable notifications for the database.

• Enable notifications for individual tables.

• Enable ASP.NET polling using "web.config" file.

• Finally use the Cache dependency object in your ASP.NET code.

Benefits and Limitations of using Cookies

Benefits

• No server resources are required as they are stored in client.

• They are light weight and simple to use.

Limitations

• Most browsers place a 4096-byte limit on the size of a cookie, although support for 8192-byte cookies is becoming more common in the new browser and client-device versions available today.

• Some users disable their browser or client device’s ability to receive cookies, thereby limiting the use of cookies.

• Cookies can be tampered and thus creating a security hole.

• Cookies can expire thus leading to inconsistency.

Object pooling in .NET

COM+ reduces overhead by creating object from scratch. So in COM+ when object is activated its activated from pool and when its deactivated it’s pushed back to the pool. Object pooling is configures by using the "ObjectPoolingAttribute" to the class.

ObjectPooling(MinPoolSize := 2, MaxPoolSize := 5, CreationTimeout := 20000)
Public Class testingclass
Inherits ServicedComponent
Public Sub DoWork()
' Method contents go here.
End Sub
End Class

Above is a sample code which has the "ObjectPooling" attribute defined. Below is a sample code which uses the class.

Public Class App
Overloads Public Shared Sub Main(args() As String)
Dim xyz As New TestObjectPooling()
xyz.doWork()
ServicedComponent.DisposeObject (xyz)
End Sub
End Class

Above is a sample code which uses the object pooled object. Note the DisposeObject() This ensures its safe return to the object pool.

What is DCOM ?

DCOM differs from COM in that it allows for creating objects distributed across a network, a protocol for invoking that object’s methods, and secures access to the object. DCOM provides a wrapper around COM, hence it is a backwards compatible extension. DCOM uses Remote Procedural Calls (RPC) using Open Software Foundation’s Distributed Computing Environment.

These RPC are implemented over TCP/IP and named pipes. The protocol which is actually being used is registered just prior to use, as opposed to being registered at initialization time. The reason for this is that if a protocol is not being used, it will not be loaded.

In order to inform an object that the client is still alive, periodic pinging is used. Hence, when the client has died and no ping has been received (to refresh it) before the expiration time, the server object will perform some clean up tasks (including decrementing its reference count).

Since RPC across a network are typically slow (compared to processes residing on the same machine), DCOM sends multiple requests in the same call. For example, in COM, the program performs a QueryInterface, one interface at a time. In DCOM, multiple QueryInterfaces are all clustered into one call.

This clustering optimization trick is also used when creating an instance of the object and serializing it with data. Since these two operations usually occur together, DCOM allows one method which will perform both operations in one call without waiting for an acknowledgment from the first task before performing the second one.

Similarly, when a client pings its server object, he can do it in one call. Moreover, if there are multiple clients sending pings to multiple servers, an optimization is made where the multiple pings going to the same object are consolidated into just one ping. This is to cut down on the use of precious bandwidth used only for pinging.

The client has the control to set the computer which will be responsible for the lifetime of the object. That is to say, these objects are not created just somewhere where the system resources and access privileges allow for it.

Call security is implemented in all four ways: authentication (to prevent false clients from impersonating the true client), authorization (to insure that a client only does what it is authorized to do), data integrity (to insure that data was not tampered with during transit) and data privacy (to insure that only designated sources can read it). The security issues are handled as they are on operating systems. The client gives the server various access privileges to access memory or disk space.

How to prevent .NET DLL to be decompiled ?

By design .NET embeds rich Meta data inside the executable code using MSIL. Any one can easily decompile your DLL back using tools like ILDASM (owned by Microsoft) or Reflector for .NET which is a third party. Secondly there are many third party tools which make this decompiling process a click away. So any one can easily look in to your assemblies and reverse engineer them back in to actual source code and understand some real good logic which can make it easy to crack your application.

The process by which you can stop this reverse engineering is using "obfuscation". It’s a technique which will foil the decompilers. There are many third parties (XenoCode, Demeanor for .NET) which provide .NET obfuscation solution. Microsoft includes one that is Dotfuscator Community Edition with Visual Studio.NET.

SharePoint from a Users Perspective

From a Users perspective SharePoint is a way of making documents and folders on the Windows platform accessible over the web. The user visits the SharePoint Portal web page, and from there they can add documents, change documents & delete documents. Through this Portal, these documents are now available for discussion, collaboration, versioning and being managed through a workflow. Hence the name "Share-Point". Details about the document can be saved too, such as: who wrote it, when, for whom, its size, and version, category or target audience. These can then be used to find the document through SharePoint's Search facility. Even documents not "in" SharePoint can be included in the search engine's index so they become part of the portal. All in all, it's a great way to get stuff up on the web for users with average technical skills, and for administrators to manage the content.

SharePoint from an Administration Perspective

Administering SharePoint mainly consists of setting it up, which is much easier than you expect, adding the content, which can be just dragging and dropping in whole directory structures and files, and then organizing the files better by giving them categories or other metadata. This is done either through the Web interface or through the SharePoint Client: a program what means you can access SharePoint as a Web folder and then right-click files to select options like "edit profile". Or add files by dragging them in individually or in bulk.

Setting the security is also important, using NT accounts, either NT4 or Active Directory (or both in mixed mode) you can give users access to files/folders the same way as you do in standard Windows. Users can be grouped and the groups given access privileges to help manage this better. Also SharePoint has 3 Roles that a User or Group can be given on a particular item. Readers can see the item (i.e. document/file or folder) but not change it, Authors can see and edit items and coordinators can set security privileges for the part of the system they have control over. Thus, you could set 12 different coordinators for 12 different folder trees, and they could manage who can do what within that area only.