Module

COM


Description

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

Methods

Name

Parameters

Returns

Shared

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.


Structures

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

Compatibility

All project types on all supported operating systems.

See also

COMException exception