with-com-interface

with-com-interface Macro

Summary

Used to simplify invocation of several methods from a particular COM interface pointer.

Package

com

Signature

with-com-interface disp interface-ptr {form}* => values

disp ::= (dispatch-function interface-name)

Arguments

`disp`	The names of the dispatch function and interface.
`interface-ptr`⇩	A form which is evaluated to yield a COM interface pointer that implements `interface-name`.
`form`⇩	A form to be evaluated.
`dispatch-function`⇩	A symbol.
`interface-name`⇩	A symbol which names the COM interface. It is not evaluated.

Values

values⇩

The values returned by the last form.

Description

The macro with-com-interface evaluates each form in a lexical environment where dispatch-function is defined as a local macro.

dispatch-function can be used to invoked the methods on interface-ptr for the COM interface interface-name, which should be the type or a supertype of the actual type of interface-ptr.

dispatch-function has the following signature:

dispatch-function method-name arg* => values

where:

`method-name`	A symbol which names the method. It is not evaluated.
`arg`	Arguments to the method (see 1.8.1 Data conversion when calling COM methods for details).
`values`	Values from the method (see 1.8.1 Data conversion when calling COM methods for details).

Examples

This example invokes the COM method GetTypeInfo in the interface IDispatch.

(defun get-type-info (disp tinfo &key
                      (locale LOCALE_SYSTEM_DEFAULT))
  (multiple-value-bind (hres typeinfo)
      (with-com-interface (call-disp i-dispatch) disp
        (call-disp get-type-info tinfo locale))
    (check-hresult hres 'get-type-info)
    typeinfo))