Module

COM

Description

Classes and functions to deal with COM components (i.e. ActiveX Controls and Automation).

Methods

Name	Parameters	Returns
FreeVARIANT	oleVariant As MemoryBlock
IIDFromString	iidString As String	MemoryBlock
RBVariantToVARIANT	v As Variant, addByref As Boolean = False	MemoryBlock
StringFromIID	iid As Ptr	String
VARIANTToRBVariant	oleVar As Ptr	Variant

Method descriptions

COM.FreeVARIANT

FreeVARIANT(oleVariant As MemoryBlock)

Frees an OLE VARIANT.

' oleVar holds an OLE VARIANT which contains a BSTR that needs to be freed
Var oleVar As MemoryBlock = COM.RBVariantToVARIANT("test")

' ... use oleVar

COM.FreeVARIANT( oleVar )

' Note: it is ok to free any type of OLE VARIANT, for example,
'       if the OLE VARIANT contains an Integer, calling FreeVARIANT is harmless

COM.IIDFromString

IIDFromString(iidString As String) As MemoryBlock

Converts an IID string representation of the form {B1EFC382-9355-11D0-835C-00AA003CCABD} to an actual IID.
Var iid As MemoryBlock
iid = COM.IIDFromString( "{B1EFC382-9355-11D0-835C-00AA003CCABD}" )

COM.RBVariantToVARIANT

RBVariantToVARIANT(v As Variant, addByref As Boolean = False) As MemoryBlock

Converts an RB Variant to an OLE VARIANT. If addByref is True then the VARIANT type will include VT_BYREF.
' oleVar holds an OLE VARIANT which contains a BSTR that needs to be freed
Var oleVar As MemoryBlock = COM.RBVariantToVARIANT("test")

' ... use oleVar

COM.FreeVARIANT( oleVar )

COM.StringFromIID

StringFromIID(iid As Ptr) As String

Converts an IID to a string representation of the form {B1EFC382-9355-11D0-835C-00AA003CCABD}.
Var iid As MemoryBlock
iid = COM.IIDFromString( "{21D6D48E-A88B-11D0-83DD-00AA003CCABD}" )

MessageBox COM.StringFromIID( iid )

COM.VARIANTToRBVariant

VARIANTToRBVariant(oleVar As Ptr) As Variant

Converts an OLE VARIANT to an RB Variant.

Var oleVar As MemoryBlock = COM.RBVariantToVARIANT( 2012 )
Var v As Variant = COM.VARIANTToRBVariant( oleVar )

Notes

Refer to the Microsoft COM documentation for full details on all classes, constants, structures, etc. used by COM.

Classes

Each class is described in its own section:

Name	Super Class	Description
IUnknown		The common interface supported by all COM objects
IDispatch	IUnknown	The common interface exposed by Automation servers
IEnumVARIANT	IUnknown	This interface provides a way to enumerate a collection of variants
IPicture	IUnknown	This interface manages a picture object and its properties. Get the details here.
COMException	RuntimeException	Raised when a COM exception is encountered

Result

Class Constant	Description
S_OK	Result returned without error.
S_FALSE	Result returned with an error.

Invoke

These constants can be passed as flags to the IDispatch.Invoke method:

Class Constant	Description
DISPATCH_METHOD	The member is invoked as a method. If a property has the same name, both this and the DISPATCH_PROPERTYGET flag may be set.
DISPATCH_PROPERTYGET	The member is retrieved as a property or data member.
DISPATCH_PROPERTYPUT	The member is changed as a property or data member.
DISPATCH_PROPERTYPUTREF	The member is changed by a reference assignment, rather than a value assignment. This flag is valid only when the property accepts a reference to an object.

Size Constants

These constants represent the sizes of common COM structures:

Class Constant	Description
SIZEOF_PTR	The size in bytes of a pointer. This value is platform-dependent: 4 on 32-bit systems and 8 on 64-bit systems.
SIZEOF_VARIANT	The size in bytes of an OLE VARIANT structure.

Locale Constants

Used to specify the locale for COM calls such as IDispatch.Invoke:

Class Constant	Description
LOCALE_USER_DEFAULT	The default locale for the current user.

Structures

Used for a variety of COM calls. Refer to Microsoft's documentation for details.

Compatibility

Project Types	Console, Desktop, Web
Operating Systems	Windows