ComImportAttribute Class
Indicates that the attributed type was previously defined in COM.
Assembly: mscorlib (in mscorlib.dll)
The ComImportAttribute type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | Equals | Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() | GetHashCode | Returns the hash code for this instance. (Inherited from Attribute.) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | IsDefaultAttribute | When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.) |
![]() | Match | When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.) |
![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
| Name | Description | |
|---|---|---|
![]() ![]() | _Attribute::GetIDsOfNames | Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.) |
![]() ![]() | _Attribute::GetTypeInfo | Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.) |
![]() ![]() | _Attribute::GetTypeInfoCount | Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.) |
![]() ![]() | _Attribute::Invoke | Provides access to properties and methods exposed by an object. (Inherited from Attribute.) |
You can apply this attribute to classes or interfaces, although the Tlbimp.exe (Type Library Importer) typically applies it for you when it imports a type library.
ComImportAttribute is a pseudo-custom attribute that indicates that a type has been defined in a previously published type library. The common language runtime treats these types differently when activating, exporting, coercing, and so on.
Note |
|---|
All base COM types that are inherited by a managed object must aggregate the Free Threaded Marshaller (FTM). COM types that do not aggregate the FTM can't be inherited by managed objects. |
The following example demonstrates how to apply the ComImportAttribute to a managed interface declaration. You apply this attribute only when generating an interop assembly manually in source code, and want to simulate the metadata produced by Tlbimp.exe.
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(); } };
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.
