What does HRESULT 0x80040064 (DV_E_FORMATETC) mean?

DV_E_FORMATETC

Invalid FORMATETC structure

DV_E_FORMATETC is HRESULT 0x80040064. It means an OLE/COM data-transfer operation rejected the supplied FORMATETC description. FORMATETC describes the requested clipboard format, target device, display aspect, index, and acceptable storage media.

What to check

• Verify cfFormat is the intended registered clipboard format.
• Initialize dwAspect and normally use DVASPECT_CONTENT unless another aspect is explicitly supported.
• Check lindex; many formats require -1.
• Make sure the tymed mask intersects the media types advertised by the data object.
• If ptd is non-null, validate the complete DVTARGETDEVICE buffer and its offsets.

Keep the exact IDataObject method together with the rejected FORMATETC. For QueryGetData or GetData, compare it with the formats returned by EnumFormatEtc; do not silently “repair” the descriptor before recording the failing values.

Related results

DV_E_TYMED specifically points to an unsupported storage-medium choice. DV_E_DVTARGETDEVICE points to the target-device descriptor. DV_E_FORMATETC is the broader rejection of the requested format contract.

Example

A drag source leaves dwAspect uninitialized and asks for TYMED_HGLOBAL. Initializing the structure with DVASPECT_CONTENT, lindex = -1, and a medium supported by the destination resolves the mismatch.

References

• Microsoft: FORMATETC structure
• Microsoft: IDataObject
• Microsoft: ReleaseStgMedium