IEnumFilters::Next
| Microsoft DirectShow 9.0 |
IEnumFilters::Next
The Next method retrieves the specified number of filters in the enumeration sequence.
Syntax
HRESULT Next( ULONG cFilters, IBaseFilter **ppFilter, ULONG *pcFetched );
Parameters
cFilters
[in] Number of filters to retrieve.
ppFilter
[out] Array of size cFilters that is filled with IBaseFilter interface pointers. The caller must release the interfaces.
pcFetched
[out] Receives the number of filters retrieved. Can be NULL if cFilters is 1.
Return Values
| Value | Description |
| S_FALSE | Did not retrieve as many filters as requested. |
| S_OK | Success. |
| E_INVALIDARG | Invalid argument. |
| E_POINTER | Null pointer argument. |
| VFW_E_ENUM_OUT_OF_SYNC | The graph has changed and is now inconsistent with the enumerator. |
Remarks
If the method succeeds, the IBaseFilter pointers all have outstanding reference counts. Be sure to release them when you are done.
If the filter graph changes (for example, the application removes a filter), the enumerator is no longer be consistent with the graph, and the method returns VFW_E_ENUM_OUT_OF_SYNC. Discard any data obtained from previous calls to the enumerator, because it might be invalid. Update the enumerator by calling the IEnumFilters::Reset method. You can then call the Next method safely.
Requirements
Header: Declared in Strmif.h; include Dshow.h.
Library: Use Strmiids.lib.
See Also