CSourceStream::QueryId
| Microsoft DirectShow 9.0 |
CSourceStream::QueryId
The QueryId method retrieves an identifier for the pin.
Syntax
HRESULT QueryId(
LPWSTR *Id
);
Parameters
Id
Pointer to a variable that receives a string containing the pin identifier.
Return Value
Returns an HRESULT value. Possible values include those shown in the following table.
| Value | Description |
| S_OK | Success. |
| E_OUTOFMEMORY | Insufficient memory. |
| E_POINTER | NULL pointer argument. |
| VFW_E_NOT_FOUND | Pin was not found on the filter. |
Remarks
This method implements the IPin::QueryId method. To construct an identifier string, the pin calls the CSource::FindPinNumber method with itself as the parameter. The FindPinNumber method returns the pin number, indexed from zero. QueryId increments the return value by one and converts the result to a string. For example, the first pin becomes "1"; the second pin becomes "2"; and so forth.
If this method returns VFW_E_NOT_FOUND, it indicates that the filter's array of pins is invalid, presumably caused by a bug in the filter.
Requirements
** Header:** Declared in Source.h; include Streams.h.
** Library:** Use Strmbase.lib (retail builds) or Strmbasd.lib (debug builds).
See Also