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
VARIANT).

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:

[uuid(21602F40-CC62-11d4-AA2B-00A0CC39CFE0)]
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 : http://vcfaq.mvps.org/com/4.htm

Is This Answer Correct ?    0 Yes 3 No

Post New Answer

More COM DCOM Interview Questions

How do you make a NET component talk to a COM component?

3 Answers   TCS,


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

1 Answers  


What are the purposes of AddRef, Release and QueryInterface functions

2 Answers  


Define and explain about COM?

0 Answers  


How can would you create an instance of the object in COM

2 Answers  


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

1 Answers  


Can you explain what is dcom?

0 Answers  


What is the difference between aggregated and contained objects?

0 Answers  


hi,I have applied for NIC test plz if any one have test paper pattrn plz send me on "mn_mayank38@yahoo.co.in"

1 Answers  


How does a DCOM component know where to instantiate itself?

1 Answers  


how to call a dll as a COM dll?

0 Answers  


What is dcom?

0 Answers  


Categories