Читать книгу AutoCAD Platform Customization - Ambrosius Lee - Страница 10

VBA is often overlooked as one of the options available to extend the AutoCAD program. There is no additional software to purchase, but you must download and install a release-specific secondary component to use VBA. You can leverage VBA to perform simple tasks, such as inserting a title block with a specific insertion point, scale, and rotation and placing the block reference on a specific layer. To perform the same tasks manually, end users would have to first set a layer as current, choose the block they want to insert, and specify the properties of the block, which in the case of a title block are almost always the same.

The VBA programming language and AutoCAD Object library can be used to do the following:

• Create and manipulate graphical objects in a drawing, such as lines, circles, and arcs

• Create and manipulate nongraphical objects in a drawing, such as layers, dimension styles, and named views

• Perform mathematical and geometric calculations

• Request input from or display messages to the user at the Command prompt

• Interact with files and directories in the operating system

• Read from and write to external files

• Connect to applications that support ActiveX and COM

• Display user forms and get input from the end user

VBA code statements are entered into the Visual Basic Editor and stored in a DVB file. Once a VBA project has been loaded, you can execute the macros through the Macros dialog box. Unlike standard AutoCAD commands, macros cannot be executed from the Command prompt, but once executed, a macro can prompt users for values at the Command prompt or with a user form. It is possible to execute a macro from a command macro that is activated with a command button displayed in the AutoCAD user interface or as a tool on a tool palette.