Microsoft .NET Framework

Editor's Notes

• #15: Inside the .NET Framework Standards Compliance Microsoft .NET is built on standards. Both the Common Language Infrastructure, CLI and Visual C# have been submitted to the ECMA for approval and adoption. The data and Web services are built on XML and SOAP. .Net Framework supports Web standards: HTML- Hyper-Text Markup Language XML - Extensible Markup Language, the universal format for structured documents and data on the Web. WSDL- Web Services Description Language (WSDL) SOAP - Simple Object Access Protocol, a simple, XML-based protocol for exchanging structured and type information on the Web. The protocol contains no application or transport semantics, which makes it highly modular and extensible. (SOAP currently still has no encryption support either) XPATH - XML Path Language XSLT - XSL Transformations (XSLT), is an XML-based language that enables you to transform one class of XML document to another.
• #16: The Common Language Runtime Features The Common Language Runtime (CLR) is the execution engine for .NET Framework applications. It provides a number of services including: Code management (loading and execution) Application memory isolation Verification of type safety Conversion of IL to native code Access to metadata (enhanced type information) Managing memory for managed objects Enforcement of Code Access Security Exception handling including cross-language exceptions Interoperation between managed code, COM objects and pre-existing DLLs (unmanaged code and data) Automation of object layout Support for developer services (profiling, debugging, etc.) Native Code is code compiled to processor-specific machine code. Managed Code runs under a "contract of cooperation" with the CLR and it must supply the metadata necessary for the CLR to provide services such as memory management, cross-language integration, Code Access Security and automatic lifetime control of objects. All code based on Microsoft Intermediate Language (MSIL) executes as managed code. Microsoft Intermediate Language (MSIL) is used as the output of a number of compilers and as the input to a Just-In-Time (JIT) compiler. The CLR includes several JIT compilers for converting MSIL to native code.
• #27: The Common Language Runtime Compilation and Execution The above diagram illustrates the process used to compile and execute managed code, or code that uses the CLR. Source code written in Visual C#, Visual Basic .NET or another language that targets the CLR is first transformed into MSIL by the appropriate language compiler. Before execution, this MSIL is compiled by the Just-in-Time (JIT) complier into native code for the processor on which the code will operate. The default is to JIT compile each method when it is first called, but it is also possible to “preJIT” MSIL code to native code at assembly install-time. With this option, all methods are compiled before the application is loaded so as to avoid the overhead of JIT compilation on each initial method call. You use the Native Image Generator (Ngen.exe) to create a native image from a managed assembly and install it into the native image cache. Once the code is compiled and cached, the CLR does not need to re-compile the MSIL code until the assembly is updated, the Just-In-Time compiled code is removed from the cache, or the machine is restarted. All languages targeting the CLR *should* exhibit a similar performance. While some compilers may produce better MSIL code, large variations in execution speed are unlikely.
• #36: First, let’s drill into the Base Framework. The Base Framework is the most important part of the .NET Framework… primarily because it is the part that I worked on. But seriously, the Base Framework is super important because no matter what kind of application you are building are using you’ll end up needing to use this functionality. The system namespace contains all the base data types for the platform. Ints, floats, are defined here – arrays, strings, the root object and so forth. Within that, we have a whole slew of various base services that are consistently available in the base platform. Collections: growable arrays, hash table IO: file, streams NET: stuff that allows you to do tcpip, sockets
• #38: On top of the base classes we have the Data and Xml support. The ADO.NET supports both the tightly connected ADO style record set support that many applications use today as well as a new more loosely coupled model called that uses DataSets. This model allows for a more distributed nature style of programming that is becoming more common. We also provide the SQLTypes namespace that provide datatypes that map directly onto the types that you're accustomed to when you do database programming, say in TSQL. Nullable datatypes. Things that can basically have an int value, or be NULL. In the System.xml namespace we have all of the xml support. It truly is a world class set of functionality we’re providing here. There is of course a parser, and an xml writer – both of which are fully w3c compliant. There is a w3c dom implementation. On top of that there is an xslt for doing xsl transformations. We have an implementation of xpath that allows you to navigate data graphs in xml. And we have the serialization namespace that provides all of the core infrastructure for moving objects to xml representation and vice versa.
• #41: For your Smart client development we have Windows Forms. Windows Forms are a combination of the best from both Visual Basic and MFC. It gives you both a RAD compositional model, along with inheritance all with a completely object oriented framework. So you can build components through inheritance, then you can visually aggregate these components using a visual forms designer like you’re used to in VB. It provides a very rich component model that has a lot of design time support so you can fairly easily build new components that can have very rich and seamless integration into the platform and into any available visual design tools. Finally, in the system.drawing namespace you can find the implementation of GDI+. GDI+ is the next generation of the GDI 2D graphics support in the system. It has some really cool features for things such as alpha blending, anti-aliasing…and native support for jpeg, gif, tif and all of the web formats.
• #46: For development of applications and services that run on the server, we have the ASP.NET architecture. In System.Web.UI we have support for dynamically generating UI on the server and sending it down to clients. This is commonly in HTML, but it could also be in DHTML or even WAP for cell phones. The ASP.NET model allows you to build applications in much the same way you build client applications today: Just click and drag buttons and even higher level controls on a form. The infrastructure provides all the state management and other support. In System.Web.Services you’ll find the infrastructure for building great Xml based web services. With this support you just write classes and methods and the infrastructure handles turning the calls into SOAP. At the bottom you will find at the lower level things that are shared between web services and web ui: things like caching, configuration, security, state management and so forth.