EQuestionAnswers.com Computer/Electronics Questions and Answers
C, C++, VC++, COM/DCOM, DLL and more
#Login #Sign up  Facebook Twitter TGoogle+

#Previous question #Index of COM/DCOM Questions #Next question

C++ vTable binding

C, C++ and C# language use vtable addresses to call COM/DCOM functions. Additional COM functions are placed after IUnknown/IDispatch vtable entries. Each function takes size of pointer and function can be called adding the offset in the vtable. This is the mechanism of C++ compiler to support inheritance and pure virtual functions.

VB, JAVA, scripting ID binding

VB, JAVA, scripting language does not work on vtable entries to call interface functions. Java and Scripting languages are run time compilable and thus vtable mechanism cannot be fit. IDispatch interface can fill this gap. It provides four additional functions to know the interface functions and types at runtime.

Programming languages other that C/C++/C# can call GetIDsOfNames with the function name and get the DISP ID number. This DISP ID number can be passed to Invoke routine to call the same function. GetTypeInfoCount and GetTypeInfo function can be called to get type information of the interface. Thus IDispatch interface can support both C/C++/C# as well as other languages like JAVA,VB,JAVA scripts. This is why IDispatch is known as dual interface.

You have viewed 1 page out of 66. Your COM/DCOM learning is 0.00% complete. Login to check your learning progress.

 Vote 0

Similar topics related to this section

# COM DCOM Interview Questions and Answers :: ALL Interview .com
# COM DCOM - COM DCOM Interview Questions
# COM interview questions | TechInterviews
# COM Interview Questions - CodeProject
# Com Dcom Interview Questions - Com and Dcom in Asp Net
# ATL Interview Questions and Answers :: ALL Interview .com
# ActiveX Interview Questions and Answers :: ALL Interview .com

* #1 webmaster Fri 02 May/2014 14:34:27(GMT)  Like 0 Unlike 0

Dear Users,

We are pleased to inform you that a forum/blog has been incorporated with www.mybestnotes.co.in. You are welcomed to add your comments, requests, codes, solutions and feedback to it. Please login(if already a member) or signup(for free) to avail to this facility.


Your message goes here:

My Post:*
Secutiry Code: ******  *
Preview this compose before posting this in discussion forum.
  1. Use [Sxx] code to show smiles. Example [S02]
  2. Use [URL ], example [URL http://www.google.com/]
  3. To display code or un formatted text use [CODE] [/CODE]. Example: [CODE] printf("Hello world"); [/CODE]
 [S01]   [S02]   [S03]   [S04]   [S05]   [S06]   [S07]   [S08] 
 [S09]   [S10]   [S11]   [S12]   [S13]   [S14]   [S15]   [S16] 
 [S17]   [S18]   [S19]   [S20]   [S21]   [S22]   [S23]   [S24] 

Note: Only members are allowed, * fields are mandatory.