ICallFrameEvents::OnCall method (callobj.h)

Article
10/13/2021

Informs the event sink if it receives a method call on the interceptor. The sink is provided with an ICallFrame instance which is bound to the intercepted incoming method invocation. Through that sink the call frame can be manipulated in various ways.

Syntax

HRESULT OnCall(
  [in] ICallFrame *pFrame
);

Parameters

[in] pFrame

A call frame bound to the just-received invocation.

Return value

This method can return the following values.

Return code	Description
S_OK	The method completed successfully.
E_UNEXPECTED	An unexpected error has occurred.

Remarks

On return from OnCall, the interceptor assumes that by some means the out-values of the method have been appropriately initialized as needed, if any; the interceptor does not itself manipulate the call frame further in any way. Typically, the OnCall implementation will have set the out-values by some means, either by invoking the call frame on an object, successfully unmarshalling some previously marshaled out-values, or clearing them with ICallFrame::Free.

The return value should also have been appropriately set during the call in a similar manner. See ICallFrame::SetReturnValue.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	callobj.h