Pointer to record

[saif]

Hi everyone

I am trying to build a COM dll. can any body tell me what parameter type should be selected to get pointer to record?

Also how can i pass safearray to COM dll?

Thanks
Saif

 

[GreenKnight]

A pointer (which is essentially the address) of a record can be found using the '@' operator.

So if you have the following:
[tt]
type
TMyFirstRecord = record
Field1 : integer;
end;

var
lMyRecord : TMyFirstRecord;
[/tt]

you should pass something like "@lMyrecord" as the parameter that requires the address.

SafeArrays:
Use a Variant array, and do something like this:
[tt]
var
lArray : Variant;
lpArray : PSafeArray;

{...sample code...}
{ Safe array of 4 integers = [7, 3, 4, 2]. }
lStateArray := VarArrayCreate( [0, 3], varInteger );
lStateArray[0] := 7;
lStateArray[1] := 3;
lStateArray[2] := 4;
lStateArray[3] := 2;

lpStateArray := PSafeArray(TVarData( lArray ).VArray );

[/tt]

 

[saif]

Dear GreenKnight

your answer is not enough. The question is how I pass safearray to my COM component. whenever I tried to pass safearray to my COM compnent it gives me error "Type not allowed in Variant Dispatch call" at compile time. And my interface is derived from IUnknown.


And I know how can i get pointer of record but I want to know what type I should declare in my COM method so that it can get Pointer.


Saif

 

[GreenKnight]

I think anything passed to a COM dll must be a pointer. Thus you would want to pass a PSafeArray into the dll, and also define it as a PSafeArray.

Are you writing this DLL, and defining the interface?

 

[McMerfy]

If you want to pass a pointer to your COM dll you should convert your pointer to OleVariant. Actually it's possible to pass a pointer as an Integer. You just can't pass Pointer types variables.

--- markus