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VarEnum Enumeration

.NET Framework 4

Indicates how to marshal the array elements when an array is marshaled from managed to unmanaged code as a UnmanagedType.SafeArray.

Namespace: System.Runtime.InteropServices
Assembly: mscorlib (in mscorlib.dll)

Syntax

C++

Copy

[SerializableAttribute]
[ComVisibleAttribute(true)]
public enum VarEnum

Members

	Member name	Description
	VT_EMPTY	Indicates that a value was not specified.
	VT_NULL	Indicates a null value, similar to a null value in SQL.
	VT_I2	Indicates a short integer.
	VT_I4	Indicates a long integer.
	VT_R4	Indicates a float value.
	VT_R8	Indicates a double value.
	VT_CY	Indicates a currency value.
	VT_DATE	Indicates a DATE value.
	VT_BSTR	Indicates a BSTR string.
	VT_DISPATCH	Indicates an IDispatch pointer.
	VT_ERROR	Indicates an SCODE.
	VT_BOOL	Indicates a Boolean value.
	VT_VARIANT	Indicates a VARIANT far pointer.
	VT_UNKNOWN	Indicates an IUnknown pointer.
	VT_DECIMAL	Indicates a decimal value.
	VT_I1	Indicates a char value.
	VT_UI1	Indicates a byte.
	VT_UI2	Indicates an unsigned short.
	VT_UI4	Indicates an unsigned long.
	VT_I8	Indicates a 64-bit integer.
	VT_UI8	Indicates an 64-bit unsigned integer.
	VT_INT	Indicates an integer value.
	VT_UINT	Indicates an unsigned integer value.
	VT_VOID	Indicates a C style void.
	VT_HRESULT	Indicates an HRESULT.
	VT_PTR	Indicates a pointer type.
	VT_SAFEARRAY	Indicates a SAFEARRAY. Not valid in a VARIANT.
	VT_CARRAY	Indicates a C style array.
	VT_USERDEFINED	Indicates a user defined type.
	VT_LPSTR	Indicates a null-terminated string.
	VT_LPWSTR	Indicates a wide string terminated by null.
	VT_RECORD	Indicates a user defined type.
	VT_FILETIME	Indicates a FILETIME value.
	VT_BLOB	Indicates length prefixed bytes.
	VT_STREAM	Indicates that the name of a stream follows.
	VT_STORAGE	Indicates that the name of a storage follows.
	VT_STREAMED_OBJECT	Indicates that a stream contains an object.
	VT_STORED_OBJECT	Indicates that a storage contains an object.
	VT_BLOB_OBJECT	Indicates that a blob contains an object.
	VT_CF	Indicates the clipboard format.
	VT_CLSID	Indicates a class ID.
	VT_VECTOR	Indicates a simple, counted array.
	VT_ARRAY	Indicates a SAFEARRAY pointer.
	VT_BYREF	Indicates that a value is a reference.

Remarks

Used with System.Runtime.InteropServices.MarshalAsAttribute to explicitly control the element type of the SafeArray.

Examples

C++

Copy


using System;
using System.Runtime.InteropServices;

namespace MyModule
{
	// If you do not have a type library for an interface
	// you can redeclare it using ComImportAttribute.

	// This is how the interface would look in an idl file.

	//[
	//object,
	//uuid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26"),
	//dual,	helpstring("IMyStorage Interface"),
	//pointer_default(unique)
	//]
	//interface IMyStorage : IDispatch
	//{
	//	[id(1)]
	//	HRESULT GetItem([in] BSTR bstrName, [out, retval] IDispatch ** ppItem);
	//	[id(2)]
	//	HRESULT GetItems([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT)* pItems);
	//	[id(3)]
	//	HRESULT GetItemDescriptions([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT) ** ppItems);
	//	[id(4), propget]
	//	HRESULT get_IsEmpty([out, retval] BOOL * pfEmpty);
	//};

	// This is the managed declaration.

	[ComImport]
	[Guid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26")]
	public interface IMyStorage  
	{
		[DispId(1)]
		[return : MarshalAs( UnmanagedType.Interface )]
		Object GetItem( [In, MarshalAs( UnmanagedType.BStr )] String bstrName );

		[DispId(2)]
		void GetItems( [In, MarshalAs( UnmanagedType.BStr )] String bstrLocation, 
			[Out, MarshalAs( UnmanagedType.SafeArray, 
					  SafeArraySubType = VarEnum.VT_VARIANT )] out Object[] Items );


		[DispId(3)]
		void GetItemDescriptions( [In] String bstrLocation, 
			[In, Out, MarshalAs( UnmanagedType.SafeArray )] ref Object[] varDescriptions );

		bool IsEmpty 
		{
			[DispId(4)]
			[return : MarshalAs( UnmanagedType.VariantBool )]
			get;
		}
	}
}

Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference

System.Runtime.InteropServices Namespace

SafeArray

MarshalAsAttribute

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