IDataObjectImpl Class
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.