TWAIN ActiveX/Plug-in HTTP Control/SDK

COM Data Type Mapping

In order to make Dynamic (Web) TWAIN accessable from any COM-enlightened program languages, such as VC, VB, Delphi and VBScript, only variant compliant IDL data types are used in the Dynamic (Web) TWAIN interface.

The following table is the mapping between different languages:

COM Type	Visual Basic Mapping	Java(J++) Mapping	C/C++ Mapping	Delphi Mapping	C# .NET Mapping	VB .NET Mapping
VARIANT_BOOL	Boolean	boolean	VARIANT_BOOL	WordBool	bool	Boolean
double	Double	double	double	Double	double	Double
float	Single	float	float	Single	float	Single
long	Long	int	long	Integer	int	Integer
short	Integer	short	short	SmallInt	short	Short
BSTR	String	java.lang.String	BSTR	WideString	string	String
DATE	Date	double	DATE	TDateTime	System.DateTime	Date
IDispatch*	Object	java.lang.Object	IDispatch*	IDispatch	Dispatch	Object
IUnknow*	Interface reference	com.ms.com.Variant	VARIANT	IUnknown	object	Object
VARIANT	Variant	com.ms.com.Variant	VARIANT	OleVariant	object	Object
CY/CURRENCY	Currency	long	CY/CURRENCY	Currency	decimal	Decimal

Out of the consideration of convenience, the Visual Basic data types are chosen to present the data types in this document. Using the preceding table, the VB data type can be easily mapped to C++, Delphi, C#.NET and VB.NET.

For other programming languages, please consult the accompanying document. Dynamic (Web) TWAIN is designed to be used in any COM compatible development environments.