Iuknown interface, DOT NET Programming

Describe IUKNOWN interface

All COM object supports atleast one interface, that is  IUnknown interface. All interfaces are the classes, derived from the base class IUnknown. Every interface supports methods access data and perform operations transparently to the programmer. taking example, IUnknown supports 3 methods, AddRef, Release(), & QueryInterface(). Assuming that pinterf is a pointer to an IUnknown. pinterf->AddRef() increments the reference count. pinterf->Release() decrements the reference count, deleting the object when the reference count reaches 0(zero). pinterf->QueryInterface( IDesired,pDesired) checks to watch  if the current interface (IUnknown) supports another interface, IDesired, creates an instance (via a call to CoCreateInstance()) of the object if the reference count is 0 (the object does not yet exist), and then calls pDesired->AddRef() to increment the reference count (where pDesired is a pointer to IDesired) and returns the pointer to the caller.

Posted Date: 9/21/2012 7:26:27 AM | Location : United States







Related Discussions:- Iuknown interface, Assignment Help, Ask Question on Iuknown interface, Get Answer, Expert's Help, Iuknown interface Discussions

Write discussion on Iuknown interface
Your posts are moderated
Related Questions
What are benefits and limitations of using Cookies? The benefits of using cookies for state management are as follows:- 1)    There is no server resources required as they a


What is Microsoft Intermediate Language (MSIL)? The .NET Framework is shipped with compilers of all .NET programming languages to develop programs. There are separate compilers

What is DMAIC and DMADV? The Six Sigma has two key methodologies viz. DMAIC and DMADV. The DMAIC is used to improve an existing business process. While DMADV is used to create

Webservices as such do not have any mechanism by which they can maintain their state. The Webservices can access ASP.NET intrinsic objects such as application, session and many mor

Need a K2 Blackpearl workflows help Need a K2 Blackpearl workflows experienced developer to integrate in SharePoint 2010 and 2013. The workflow integrates with Navision 5 provid

I want a Panel for youtube views and facbook likes. I need a panel made that can increase facebook fanpage likes, and that will increase youtube video views. Youtube views an

what are major difference between classic ADO &ADO.NET?

Print Triangle in Reverse Pattern - C# Program Need the code of C# Program for Print Triangle in Reverse Pattern.

Php project for Narivramanarao For email Project Description: This is a project for Narivramanarao for emails and for php.rar please bid on the project and let's get started