vlaxcreateobject

vlax-create-object is a Visual LISP function used to create a COM (ActiveX) automation object from a programmatic identifier (ProgID) or CLSID. It enables AutoCAD and other VLisp environments to automate external Windows applications and components that expose COM interfaces, such as Microsoft Office applications or custom automation servers. The object returned is a COM wrapper that can be manipulated with VLisp’s automation helpers.

Syntax and parameters:

The typical usage is (vlax-create-object progid [server]). The progid is a string that identifies the COM class (for example, "Excel.Application"). The optional server argument can specify a remote computer name for DCOM activation, with local activation being the common case. The function returns a vlax-ole-object on success or nil if creation fails.

Return value and usage:

The returned object is a COM automation object (vlax-ole-object). You interact with it through vlax helper functions such as vlax-put-property, vlax-get-property, and vlax-invoke-method. Example usage often includes launching an application, making it visible, performing actions, and then releasing resources:

(setq xl (vlax-create-object "Excel.Application"))

(vlax-put-property xl 'Visible :t)

(setq wb (vlax-invoke-method (vlax-get-property xl 'Workbooks) 'Add))

; perform operations on the workbook

(vlax-invoke-method xl 'Quit)

(vlax-release-object wb)

(vlax-release-object xl)

Notes:

- The target ProgID must be registered on the system; otherwise the call fails.

- COM automation depends on the bitness and permissions of the host and target applications; ensure compatibility between AutoCAD/VLisp and the external COM server.

- Use vlax-release-object when the automation object is no longer needed to free resources.

See also:

Related functions include vlax-get-property, vlax-put-property, and vlax-invoke-method, which are used to read, set, and call methods on COM objects.