Types of compatibility in vb6, DOT NET Programming

What are types of compatibility in VB6

There are three possible project compatibility settings:

  • No Compatibility
  • Project Compatibility
  • Binary Compatibility

1) No Compatibility: With this Compatibility setting, new interface ID's, new class ID's,  and a new type library ID will be generated by VB every  time the ActiveX component project is compiled. This will cause any of the compiled client components to fail (with error 429!) and report a missing reference to the 'VB ActiveX Test Component whenever a client project is loaded in the VB IDE.

2) Project Compatibility: With this Compatibility setting, VB will generate a new interface ID's for classes whose interfaces have changed, but will not change the class ID's or the type library ID. This will still cause any of the compiled client components to fail (with error 429!) but will not report a missing reference to the 'VB ActiveX Test Component' whenever  a client project is loaded in the VB IDE. Recompilation of the client components will restore them to the working order again.

3) Binary Compatibility: The VB makes it possible to extend an existing class or interface by adding new methods & properties etc. and yet still remain binary compatibility. It can do this, as it silently creates a new interface ID for the extended interface and adds registration code to register the original interface ID but with a new forward key having the value of this new interface ID. COM will then substitute calls having the old ID with the new ID and so applications built against the old interface will continue to work (assuming the inner workings of the component remain backward compatible!). With that setting, VB will not change any of the existing class, interface or type library ID's, however in order that it can do so, VB requires the project to specify an existing compiled version that it can compare against to assure  that the existing interfaces have not been broken.

Posted Date: 9/21/2012 7:33:53 AM | Location : United States







Related Discussions:- Types of compatibility in vb6, Assignment Help, Ask Question on Types of compatibility in vb6, Get Answer, Expert's Help, Types of compatibility in vb6 Discussions

Write discussion on Types of compatibility in vb6
Your posts are moderated
Related Questions
TFS - SpiraTeam synchronization plugin. Project Description: We would like you to develop the subsequent requirements in one plug-in already in production. The plug-in was de

This assignment requires you to design, develop and implement a token web application. It is intended to assess your mastery of the web application development concepts and ASP.NET

What is the relationship between a class and an object? A class acts as a blue-print that explains the properties, states, and behaviors that are common to a number of objects.

Using the attached XML file (xml_ind.xml) create a XSLT and CSS file for the following information: select the following information for ONLY the cars that cost more than $50,00

Write a program interactively two integers using the method console.readline and int.parse and display their sum

Project Description: i want to prepare a pollution checking software.. i have a demo of it.. Exactly someone to be created ..some changes to be included.. sms gateway t

Explain project life cycle. Figure: -Life cycle of a project There are 5 stages of any project initiating, planning, executing, controlling, & closeout. These are the

What is Service Oriented architecture? The "Services" are the components which expose well defined interfaces and these interfaces communicate through XML messages. By Using th

Implement the service architecture using both .NET and Java technologies based on the following minimum requirements for this assessment. a.  The 'Parcel transaction service' mu

What is an XMLReader Class? This is an abstract class available from the System.XML namespace. The XML reader works on a read-only stream browsing from one node to another in a