System.Variants.TCustomVariantType.OlePromotion
Delphi
function OlePromotion(const V: TVarData; out RequiredVarType: TVarType): Boolean; virtual;
C++
virtual bool __fastcall OlePromotion(const TVarData &V, /* out */ System::Word &RequiredVarType);
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
| function | protected | System.Variants.pas System.Variants.hpp |
System.Variants | TCustomVariantType |
Description
Indicates the type to which a Variant value must be cast to make it Automation-compatible.
Override OlePromotion to indicate when a Variant of this custom Variant type must be cast to another type before it can be auto-marshaled using an Automation interface.
V is the TVarData record for the custom Variant that the application wants to marshal.
RequiredVarType returns the type to which V must be cast before it is Automation-compatible.
OlePromotion returns true if V can be cast to an Automation-compatible type, false if there is no type to which V can be cast.
As implemented in TCustomVariantType, OlePromotion sets RequiredVarType to varOleStr and returns true if V does not already represent a Unicode string.