QueryReferent

Summary

The QueryReferent method queries an interface on the referent if it exists, and like nsISupports::QueryInterface, produces an owning reference to the desired interface.

 void QueryReferent(
   in nsIIDRef aIID,
   [iid_is(aIID, retval] out nsQIResult aResult
 );

Parameters

aIID

[in] The IID of the requested interface.

aResult

[out] The resulting interface pointer.

Exceptions Thrown

NS_ERROR_NULL_POINTER

The referent no longer exists.

NS_ERROR_NO_INTERFACE

The requested interface is not available.

Remarks

The caller of QueryReferent should not hold on to the produced interface permanently; that would defeat the purpose of using a non-owning nsIWeakReference in the first place.

See Also

nsISupports::QueryInterface , nsIWeakReference