Chapter 10: COM and .NET Interoperability

System.SByte

char

N/A

System.Int16

short

Integer

System.Int32

long

Long

  with UnmanagedType.Error

HRESULT

Long

System.Int64

int64

N/A

System.IntPtr

long

Long

System.Char

  default parameters

unsigned short

N/A

  default for struct fields (ANSI)

unsigned char

Byte

  default for struct fields (Unicode)

unsigned short

N/A

  with UnmanagedType.U1

unsigned char

Byte

  with UnmanagedType.U2

unsigned. short

N/A

System.UInt16

unsigned short

N/A

System.UInt32

unsigned long

N/A

  with UnmanagedType.Error

HRESULT

Long

System.UInt64

uint64

N/A

System.UIntPtr

unsigned long

N/A

System.Single

single

Single

System.Double

double

Double

System.Boolean

  default for parameters

VARIANT_BOOL

Boolean

  default for struct fields

long

Long

  with UnmanagedType.Bool

long

Long

  with UnmanagedType.I1

unsigned char

Byte

  with UnmanagedType.U1

unsigned char

Byte

  with UnmanagedType.VariantBool

VARIANT_BOOL

Boolean

System.DateTime

DATE

Date

System.Guid

GUID

N/A

System.Decimal

  default

DECIMAL

N/A

  with UnmanagedType.Currency

CURRENCY

Currency

System.String

  default for parameters

BSTR

String

  default for struct fields

LPSTR

String

  with UnmanagedType.LPStr

LPSTR

String

  with UnmanagedType.LPWStr

LPWSTR

String

  with UnmanagedType.CustomMarshaler

long

Long

System.Text.StringBuilder

LPSTR

String

  with UnmanagedType.LPStr

LPSTR

String

  with UnmanagedType.LPWStr

LPWSTR

String

  with UnmanagedType.CustomerMarshaler

IUnknown*

Unknown

System.Object

VARIANT

Variant

  default parameters

IUnknown*

Unknown

  default for struct fields

IUnknown*

Unknown

  with UnmanagedType.IUnknown

IUnknown*

Unknown

  with UnmanagedType.IDispatch

IDispatch*

Object

  with UnmanagedType.Struct

VARIANT

Variant

  with UnmanagedType.CustomerMarshaler

IUnknown*

Unknown

  with UnmanagedType.Interface

IUnknown*

Unknown

AnInterface

AnInterface*

SomeClass or Interface

  with UnmanagedType.CustomMarshaler

IUnknown*

Unknown

SomeClass

DefaultInterface*

SomeClass

  with UnmanagedType.CustomerMarshaler

IUnknown*

Unknown

SomeFormattedClass

SomeStruct*

ByRef SomeUDT

  with UnmanagedType.CustomMarshaler

IUnknown*

Unknown

SomeDelegatedClass

  default parameters

DefaultInterface*

SomeDelegatedClass

  default for struct fields

int

Long

  with UnmanagedType.FunctionPtr

int

Long

  with UnmanagedType.CustomMarshaler

IUnknown*

Unknown

SomeValueType

SomeStruct

SomeUDT

SomeEnum

  with 32-bit underlying type

SomeEnum

SomeEnum

  with any other underlying type

underlying type

underlying type

array of some type

  default parameters

SAFEARRAY(Type)

SomeType ()

  with UnmanagedType.ByValArray

SomeType [size]

SomeType (0 to −1)

  with UnmanagedType.LPArray

(parameters only)

SomeType*

SomeType

  with UnmanagedType.SafeArray

SAFEARRAY(Type)

SomeType ()

  with UnmanagedType.CustomMarshaler

long

Long

null

VT_EMPTY

System.DBNull

VT_NULL

System.Runtime.InteropServices.CurrencyWrapper

VT_CY

System.Runtime.InteropServices.UnknownWrapper

VT_UNKNOWN

System.Runtime.InteropServices.DispatchWrapper

VT_DISPATCH

System.Runtime.InteropServices.ErrorWrapper

VT_ERROR

System.Reflection.Missing

VT_ERROR

System.String

VT_BSTR

System.Decimal

VT_DECIMAL

System.Boolean

VT_BOOL

System.Char

VT_U2

System.Byte

VT_U1

System.SByte

VT_I1

System.Int16

VT_I2

System.Int32

VT_I4

System.Int64

VT_I8

System.IntPtr

VT_INT

System.UInt16

VT_U2

System.UInt32

VT_U4

System.UInt64

VT_U8

System.UIntPtr

VT_UINT

System.Single

VT_R4

System.Double

VT_R8

System.DateTime

VT_DATE

Array

VT_ARRAY

System.Object or other .NET class

VT_DISPATCH

AutomationProxy

Sets if an object should be custom marshaled or marshaled using the automation marshaler

ClassInterface

Sets the type of interface generated for a class

CoClass

Identifies the original CLSID for an object

ComImport

Indicates that a class or interface was imported to managed code

ComRegisterFunction

Sets a method to be called when an assembly is registered for use with COM

ComSourceInterfaces

Identifies the source interface for events

ComUnregisterFunction

Sets a method to be called when an assembly is unregistered for COM

ComVisible

Sets or determines if an object is visible to COM

DispId

Sets the dispatch ID for a method or property

FieldOffset

Sets the physical position of a field within a class or struct

Guid

Sets a GUID on a class or an interface

IDispatchImp

Sets which IDispatch implementation is used by managed code when exposing dual interfaces or dispinterfaces

LCIDConversion

Sets an unmanaged method signature LCID parameter

MarshalAs

Sets how data is marshaled to COM

Optional

Sets a parameter to be optional

Out

Sets a parameter as optional

PreserveSig

Suppresses HRESULT or retval signature when making COM calls

ProgId

Sets the program ID of a class

StructLayout

Sets or controls the physical layout of structs

AddRef

Adds a reference to an interface

AllocCoTaskMem

Allocates an unmanaged memory chunk

BindToMoniker

Get an interface moniker from a specified moniker

CreateWrapperOfType

Wraps a COM type with a designated type

Destroy Structure

Frees substructures of an unmanaged clock

FreeCoTaskMem

Frees an unmanaged memory chunk

GetActiveObject

Obtains an instance from the running object table (ROT)

GetComInterfaceForObject

Returns an IUnknown pointer for an object

GetFunctionPointerForDelegate

Used to pass a function pointer for a managed object to unmanaged code

IsComObject

Determines if an object is a native COM object

OffsetOf

Returns the field offset of an unmanaged object

PtrToStringXXXX (Ansi, Bstr, or Uni)

Given a pointer to an unmanaged string, returns a string object

PtrToStructure

Given a pointer to an unmanaged struct, returns a managed struct

QueryInterface

Returns a COM interface

Release

Releases a reference to an interface

StructureToPtr

Given a managed struct, returns an unmanaged copy