Microsoft DirectX 9.0

IPin::QueryId

The QueryId method retrieves an identifier for the pin.

Syntax

HRESULT QueryId(
  LPWSTR *Id
);

Parameters

Id

[out] Address of a variable that receives a string containing the pin identifier.

Return Value

Returns an HRESULT value. Possible values include the following.

Value Description
S_OK Success.
E_OUTOFMEMORY Insufficient memory.
E_POINTER Null pointer argument.

Remarks

This method supports graph persistence. Use this method to save a pin's state, and the IBaseFilter::FindPin method to restore the state. The pin's identifier string is defined by the filter implementation. The identifier must be unique within the filter.

Note   The pin identifier is not necessarily the same as the pin name that the QueryPinInfo method returns.

The filter allocates the returned string using the Microsoft® Win32® CoTaskMemAlloc function. The caller must free it using CoTaskMemFree.

See Also