nsISupports:QueryInterface

From MDC

« XPCOM API Reference

Contents 1 Summary 2 Parameters 3 Return Values 4 Exceptions Thrown 5 Remarks

[edit] Summary

The QueryInterface method provides runtime type discovery.

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

[edit] Parameters

aIID

[in] The IID of the requested interface.

aResult

[out] The resulting interface pointer.

[edit] Return Values

This method does not return a value.

[edit] Exceptions Thrown

NS_ERROR_NO_INTERFACE

The requested interface is not available.

[edit] Remarks

The interface pointer, aResult, returned by QueryInterface must be released by a call to Release when it is no longer needed. QueryInterface is a symmetric, transitive, and reflexive operator.