Differences between VB 6.0 & VB.NET

1) It is an object based programming 2)Variables or member declarations are not mandatory 3)Uses Unstructured method for handling exceptions 4) Uses DAO, RDO, ADO object models for database connectivity 5)Uses Data projects as its default reporting tool1) It is an object oriented programming 2)Here its mandatory 3) Uses Unstructured / Structured methods for handling exception 4) supports ADO and ADO.NET models 5) uses crystal reports

6)Uses COM for language interoperability 7)Does not support multi threading 8)Uses DCOM to support distributed technology 9) Supports web tech.,client side appns or server side appns can be designed using VB6) Uses .net assembly for language interoperability 7)Does support multithreading 8)Uses .net remoting to support distributed tech. 9)It does not support web technology.Note VB.net cant be used to design Client Side / Server side appns but it can used as an implementing Lang for asp.net

Differences between C#.net & VB.net

W.R.TC#.NETVB.NETDATA TYPES1.Unsigned Data Types 2.Strongly Typed Lang.1.No Unsigned Data Types 2.It is not strongly typed OOPS ConceptMore concepts in C# u have interfaces, abstraction, indexesLess Concepts here. No indexes in Vb.net and it has limitations wrt interfaceMemory Manag.Garbage Collector. Automatic releasing of resources is available. It Boosts the performance.Garbage collector, destructor,dispose.Automatic releasing of resources is not available.You have to explicitly use dispose methodOperator OverloadingIs available in C#Is not available in VB.NetPointersIs available in C#Is not available in VB.NetAuto XML Document.Is available in C#Is not available in VB.Net

ARCHITECTURE OF ASP.NETHTTP REQUEST inet_info.exeMachine.configWeb.configHTTP RESPONSEAspnet_isapi.dllAsp.dllProcess ReqWeb ServerASP.net Runtime EnvAspnet_wp.exeApp DomainHTTP Handlers(.aspx)(.asp)

Inet_info.exe identifies the request and submits the request to the aspnet_isapi.dll.Aspnet_isapi.dll is a script engine which process the .aspx pageThen the script engine will submit the request to the ASP.NET runtime env.After verifying all the security issues of both machine.config and web.config then an AppDomain will be defined for the request and after processing the request the response will be given to the client as HTTP response.Machine.Config it is used to maintain the complete configuration details of all the web applications registered on to the web server of ASP.netWeb.Config It is used to maintain the config details about a single web application.Where configuration details includes security,database connectivity,state management,trace details of the web application,,authentication and authorization of the applications and globalizations

AppDomain:All windows appns run inside a process and these process own resources such as memory and kernel objects and the threads execute code loaded into a process.Process are protected from each other by the OS. All these appns are run on high isolation mode to work safely.The disadvantage of this is memory resources are blocked.So to achieve this in a single process all the applications should be made to run which is good to an extent but the draw back is if one crashes all other are effected. So in .net the code verification feature takes care that the code is safe to run.so asp.net each application runs its own application domain and therefore it is protected from other asp.net applications on the same machine so it ignores the process isolation specified on IIS.

HTTPHandlers:ASP.net builds upon a extensible architecture known as HTTP runtime.This is responsible for handling the requests and sending the response.It is upto an individual handlers such as asp.net or web service to implement the work done on a request.IIS supports a low level API known as ISAPI for developing custom solutions like building JSP on IIS. ASP.net implements a similar concept with HTTP handlers.A request is assigned to ASP.net from IIS then ASP.net examines entries in the section based on the extension of the request to determine which handler the request should be send to.

Features of asp.netASPX,ASPSimplified Programming ModelSimplified deploymentBetter PerformanceCachingSecurityPowerful ControlsSimplified Browser SupportSimplified Form Validations

Features of asp.netCode behind PagesMore powerful data accessWeb servicesBetter session Management