IDataObjectImpl Class

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This class provides methods for supporting Uniform Data Transfer and managing connections.

Important

This class and its members cannot be used in applications that execute in the Windows Runtime.

Syntax

template<class T>  
class IDataObjectImpl

Parameters

T
Your class, derived from IDataObjectImpl.

Members

Public Methods

Name Description
IDataObjectImpl::DAdvise Establishes a connection between the data object and an advise sink. This enables the advise sink to receive notifications of changes in the object.
IDataObjectImpl::DUnadvise Terminates a connection previously established through DAdvise.
IDataObjectImpl::EnumDAdvise Creates an enumerator to iterate through the current advisory connections.
IDataObjectImpl::EnumFormatEtc Creates an enumerator to iterate through the FORMATETC structures supported by the data object. The ATL implementation returns E_NOTIMPL.
IDataObjectImpl::FireDataChange Sends a change notification back to each advise sink.
IDataObjectImpl::GetCanonicalFormatEtc Retrieves a logically equivalent FORMATETC structure to one that is more complex. The ATL implementation returns E_NOTIMPL.
IDataObjectImpl::GetData Transfers data from the data object to the client. The data is described in a FORMATETC structure and is transferred through a STGMEDIUM structure.
IDataObjectImpl::GetDataHere Similar to GetData, except the client must allocate the STGMEDIUM structure. The ATL implementation returns E_NOTIMPL.
IDataObjectImpl::QueryGetData Determines whether the data object supports a particular FORMATETC structure for transferring data. The ATL implementation returns E_NOTIMPL.
IDataObjectImpl::SetData Transfers data from the client to the data object. The ATL implementation returns E_NOTIMPL.

Remarks

The IDataObject interface provides methods to support Uniform Data Transfer. IDataObject uses the standard format structures FORMATETC and STGMEDIUM to retrieve and store data.

IDataObject also manages connections to advise sinks to handle data change notifications. In order for the client to receive data change notifications from the data object, the client must implement the IAdviseSink interface on an object called an advise sink. When the client then calls IDataObject::DAdvise, a connection is established between the data object and the advise sink.

Class IDataObjectImpl provides a default implementation of IDataObject and implements IUnknown by sending information to the dump device in debug builds.

Related Articles ATL Tutorial, Creating an ATL Project

Inheritance Hierarchy

IDataObject

IDataObjectImpl

Requirements

Header: atlctl.h

IDataObjectImpl::DAdvise

Establishes a connection between the data object and an advise sink.

HRESULT DAdvise(
    FORMATETC* pformatetc,
    DWORD advf,
    IAdviseSink* pAdvSink,
    DWORD* pdwConnection);

Remarks

This enables the advise sink to receive notifications of changes in the object.

To terminate the connection, call DUnadvise.

See IDataObject::DAdvise in the Windows SDK.

IDataObjectImpl::DUnadvise

Terminates a connection previously established through DAdvise.

HRESULT DUnadvise(DWORD dwConnection);

Remarks

See IDataObject::DUnadvise in the Windows SDK.

IDataObjectImpl::EnumDAdvise

Creates an enumerator to iterate through the current advisory connections.

HRESULT DAdvise(
    FORMATETC* pformatetc,
    DWORD advf,
    IAdviseSink* pAdvSink,
    DWORD* pdwConnection);

Remarks

See IDataObject::EnumDAdvise in the Windows SDK.

IDataObjectImpl::EnumFormatEtc

Creates an enumerator to iterate through the FORMATETC structures supported by the data object.

HRESULT EnumFormatEtc(  
    DWORD dwDirection,
    IEnumFORMATETC** ppenumFormatEtc);

Remarks

See IDataObject::EnumFormatEtc in the Windows SDK.

Return Value

Returns E_NOTIMPL.

IDataObjectImpl::FireDataChange

Sends a change notification back to each advise sink that is currently being managed.

HRESULT FireDataChange();

Return Value

A standard HRESULT value.

IDataObjectImpl::GetCanonicalFormatEtc

Retrieves a logically equivalent FORMATETC structure to one that is more complex.

HRESULT GetCanonicalFormatEtc(FORMATETC* pformatetcIn, FORMATETC* pformatetcOut);

Return Value

Returns E_NOTIMPL.

Remarks

See IDataObject::GetCanonicalFormatEtc in the Windows SDK.

IDataObjectImpl::GetData

Transfers data from the data object to the client.

HRESULT GetData(
    FORMATETC* pformatetcIn,
    STGMEDIUM* pmedium);

Remarks

The pformatetcIn parameter must specify a storage medium type of TYMED_MFPICT.

See IDataObject::GetData in the Windows SDK.

IDataObjectImpl::GetDataHere

Similar to GetData, except the client must allocate the STGMEDIUM structure.

HRESULT GetDataHere(
    FORMATETC* pformatetc,
    STGMEDIUM* pmedium);

Return Value

Returns E_NOTIMPL.

Remarks

See IDataObject::GetDataHere in the Windows SDK.

IDataObjectImpl::QueryGetData

Determines whether the data object supports a particular FORMATETC structure for transferring data.

HRESULT QueryGetData(FORMATETC* pformatetc);

Return Value

Returns E_NOTIMPL.

Remarks

See IDataObject::QueryGetData in the Windows SDK.

IDataObjectImpl::SetData

Transfers data from the client to the data object.

HRESULT SetData(
    FORMATETC* pformatetc,
    STGMEDIUM* pmedium,
    BOOL fRelease);

Return Value

Returns E_NOTIMPL.

Remarks

See IDataObject::SetData in the Windows SDK.

See Also

Class Overview