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CSourceStream::QueryId

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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