How to Use structs in COM interfaces when Automation
compatibility is not an issue?

How to Use structs in COM interfaces when Automation compatibility is not an issue?..

Answer / krishna akkulu

Structs, also known as User Defined Types (UDTs), can be
used in Automation- compatible interfaces
An Automation- compatible struct may contain only primitive
Automation types as its members.

Nesting structs is not allowed, but VARIANT is allowed thus
enabling nested structs (you can store a struct in a

In order for a struct to be usable for Automation-
compatible interfaces, the struct must be described in a
type library and it must be declared with its own GUID:

struct MyStruct
[helpstring("A long value")]
long nLongValue;

[helpstring("A string")]
BSTR bstrStringValue;

// Later in the IDL file
[uuid(...), version(...), helpstring(...)]
library MyLib
struct MyStruct;
For more info see :

Is This Answer Correct ?    0 Yes 3 No

Post New Answer

More COM DCOM Interview Questions

How does a DCOM component know where to instantiate itself?

1 Answers  

Which tool is used to configure the port range and protocols for DCOM communications?

1 Answers  

how to call a dll as a COM dll?

0 Answers  

Define and explain about COM?

0 Answers  

Suppose we have object B and aggregated object C (in- proc server), created by B. Can you access any interface of B from C?

0 Answers  

where can i use pmcmd commands of informatica

1 Answers  

What should QueryInterface functions do if requested object was not found?

1 Answers  

What happens when client calls CoCreateInstance?

2 Answers   Cap Gemini,

how you call a dll as a COM dll.

2 Answers  

Explain JIT activation?

1 Answers  

What is In-proc?

4 Answers  

hi,I have applied for NIC test plz if any one have test paper pattrn plz send me on ""

1 Answers