VarEnum Enum

Definition

Namespace:

System.Runtime.InteropServices

Assembly:

System.Runtime.InteropServices.dll

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

public enum class VarEnum

public enum VarEnum

type VarEnum = 

Public Enum VarEnum

Inheritance

Object

ValueType

Enum

VarEnum

Fields

Name	Value	Description
VT_EMPTY	0	Indicates that a value was not specified.
VT_NULL	1	Indicates a null value, similar to a null value in SQL.
VT_I2	2	Indicates a short integer.
VT_I4	3	Indicates a long integer.
VT_R4	4	Indicates a float value.
VT_R8	5	Indicates a double value.
VT_CY	6	Indicates a currency value.
VT_DATE	7	Indicates a DATE value.
VT_BSTR	8	Indicates a BSTR string.
VT_DISPATCH	9	Indicates an IDispatch pointer.
VT_ERROR	10	Indicates an SCODE.
VT_BOOL	11	Indicates a Boolean value.
VT_VARIANT	12	Indicates a VARIANT far pointer.
VT_UNKNOWN	13	Indicates an IUnknown pointer.
VT_DECIMAL	14	Indicates a decimal value.
VT_I1	16	Indicates a char value.
VT_UI1	17	Indicates a byte.
VT_UI2	18	Indicates an unsignedshort.
VT_UI4	19	Indicates an unsignedlong.
VT_I8	20	Indicates a 64-bit integer.
VT_UI8	21	Indicates an 64-bit unsigned integer.
VT_INT	22	Indicates an integer value.
VT_UINT	23	Indicates an unsigned integer value.
VT_VOID	24	Indicates a C style void.
VT_HRESULT	25	Indicates an HRESULT.
VT_PTR	26	Indicates a pointer type.
VT_SAFEARRAY	27	Indicates a SAFEARRAY. Not valid in a VARIANT.
VT_CARRAY	28	Indicates a C style array.
VT_USERDEFINED	29	Indicates a user defined type.
VT_LPSTR	30	Indicates a null-terminated string.
VT_LPWSTR	31	Indicates a wide string terminated by null.
VT_RECORD	36	Indicates a user defined type.
VT_FILETIME	64	Indicates a FILETIME value.
VT_BLOB	65	Indicates length prefixed bytes.
VT_STREAM	66	Indicates that the name of a stream follows.
VT_STORAGE	67	Indicates that the name of a storage follows.
VT_STREAMED_OBJECT	68	Indicates that a stream contains an object.
VT_STORED_OBJECT	69	Indicates that a storage contains an object.
VT_BLOB_OBJECT	70	Indicates that a blob contains an object.
VT_CF	71	Indicates the clipboard format.
VT_CLSID	72	Indicates a class ID.
VT_VECTOR	4096	Indicates a simple, counted array.
VT_ARRAY	8192	Indicates a SAFEARRAY pointer.
VT_BYREF	16384	Indicates that a value is a reference.

Examples

using namespace System;
using namespace System::Runtime::InteropServices;

// 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")]
interface class IMyStorage
{
   [DispId(1)]
   Object^ GetItem( [In,MarshalAs(UnmanagedType::BStr)]String^ bstrName );

   //[return : MarshalAs(UnmanagedType::Interface)]

   [DispId(2)]
   void GetItems( [In,MarshalAs(UnmanagedType::BStr)]String^ bstrLocation, [Out,MarshalAs(UnmanagedType::SafeArray,
   SafeArraySubType=VarEnum::VT_VARIANT)]array<Object^>^Items );

   [DispId(3)]
   void GetItemDescriptions( [In]String^ bstrLocation, [In,Out,MarshalAs(UnmanagedType::SafeArray)]array<Object^>^varDescriptions );

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

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;
        }
    }
}

Imports System.Runtime.InteropServices

Module 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)> _
        Function GetItem(<InAttribute(), MarshalAs(UnmanagedType.BStr)> ByVal bstrName As String) _
           As <MarshalAs(UnmanagedType.Interface)> Object

        <DispId(2)> _
        Function GetItems(<InAttribute(), MarshalAs(UnmanagedType.BStr)> ByVal bstrLocation As String, _
           <OutAttribute(), MarshalAs(UnmanagedType.SafeArray, SafeArraySubType := VarEnum.VT_VARIANT)> _
                                      ByVal Items() As Object)

        <DispId(3)> _
        Function GetItemDescriptions(<InAttribute()> ByVal bstrLocation As String, _
           <InAttribute(), OutAttribute(), _
                      MarshalAs(UnmanagedType.SafeArray)> ByRef varDescriptions() As Object)

        <DispId(4)> _
        ReadOnly Property IsEmpty(<MarshalAs(UnmanagedType.VariantBool)> ByVal bEmpty As Boolean)

    End Interface
End Module

Remarks

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

See also

• SafeArray
• MarshalAsAttribute