IDataObject::GetData method (objidl.h)

Článek
10/13/2021

Called by a data consumer to obtain data from a source data object. The GetData method renders the data described in the specified FORMATETC structure and transfers it through the specified STGMEDIUM structure. The caller then assumes responsibility for releasing the STGMEDIUM structure.

Syntax

HRESULT GetData(
  [in]  FORMATETC *pformatetcIn,
  [out] STGMEDIUM *pmedium
);

Parameters

[in] pformatetcIn

A pointer to the FORMATETC structure that defines the format, medium, and target device to use when passing the data. It is possible to specify more than one medium by using the Boolean OR operator, allowing the method to choose the best medium among those specified.

[out] pmedium

A pointer to the STGMEDIUM structure that indicates the storage medium containing the returned data through its tymed member, and the responsibility for releasing the medium through the value of its pUnkForRelease member. If pUnkForRelease is NULL, the receiver of the medium is responsible for releasing it; otherwise, pUnkForRelease points to the IUnknown on the appropriate object so its Release method can be called. The medium must be allocated and filled in by GetData.

Return value

This method returns S_OK on success. Other possible values include the following.

Return code	Description
DV_E_LINDEX	The value for lindex is not valid; currently, only -1 is supported.
DV_E_FORMATETC	The value for pformatetcIn is not valid.
DV_E_TYMED	The tymed value is not valid.
DV_E_DVASPECT	The dwAspect value is not valid.
OLE_E_NOTRUNNING	The object application is not running.
STG_E_MEDIUMFULL	An error occurred when allocating the medium.
E_UNEXPECTED	An unexpected error has occurred.
E_INVALIDARG	The dwDirection value is not valid.
E_OUTOFMEMORY	There was insufficient memory available for this operation.

Remarks

A data consumer calls GetData to retrieve data from a data object, conveyed through a storage medium (defined through the STGMEDIUM structure).

Notes to Callers

You can specify more than one acceptable tymed medium with the Boolean OR operator. GetData must choose from the OR'd values the medium that best represents the data, do the allocation, and indicate responsibility for releasing the medium.

Data transferred across a stream extends from position zero of the stream pointer through to the position immediately before the current stream pointer (that is, the stream pointer position upon exit).

Notes to Implementers

GetData must check all fields in the FORMATETC structure. It is important that GetData render the requested aspect and, if possible, use the requested medium. If the data object cannot comply with the information specified in the FORMATETC, the method should return DV_E_FORMATETC. If an attempt to allocate the medium fails, the method should return STG_E_MEDIUMFULL. It is important to fill in all of the fields in the STGMEDIUM structure.

Although the caller can specify more than one medium for returning the data, GetData can provide only one medium. If the initial transfer fails with the selected medium, this method can be implemented to try one of the other media specified before returning an error.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	objidl.h

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