AutoCAD Basic Modify Command

Next, you'll introduce a few basic, generic, change commands. For most AutoCAD commands, users can usually use two editing methods: One is to start the command, then select the object to edit, the other is to select the object first, and then edit the command at the call. In order to describe the unification, the first method is used in this chapter to modify. A command that can only use one editing method is described in the instructions for that command.

5.1.1 Erase (delete) command

The delete command deletes one or more objects selected by the user in the graph. For a deleted object, although the user does not see it on the screen, the object remains in the graphics database until the graphics file has been closed, and the user can use the Undo or oops command to recover. When a graphics file is closed, the object is permanently deleted.

The command is invoked in the following ways:

Toolbar: "Modify (modified)" →

Menu: "Modify (modified)" → "Erase (delete)"

Shortcut menu: Right-click after selecting the Object, pop-up shortcut menu, select Erase Item

Command line: Erase (or alias E)

When this command is invoked, the user is prompted to select the object:

Select objects:

The user can construct the object selection set at this prompt and enter to determine.

5.1.2 Move (moves) command

The move command can pan one or more objects of the user's choice to another location without changing the orientation and size of the object.

The command is invoked in the following ways:

Toolbar: "Modify (modified)" →

Menu: "Modify (modified)" → "Move"

Shortcut menu: Right-click after selecting Object, popup shortcut menu, select Move Item

Command line: Move (or alias M)

When this command is invoked, the user is prompted to select the object:

Select objects:

The user can construct the selection set of the object to be moved at this prompt, and enter to determine, the system further prompts:

Specify base point or displacement:

The user is asked to specify a base point, where the user can determine the basis by keyboard input or mouse selection, when the system prompts:

Specify second point of displacement or <use as Displacement>:

At this point the user has two choices:

(1) Specifies the 2nd: The system will determine the moving distance and direction of the selected object according to the distance and direction between the base point and the 2nd. In this case, the effect of the move is only related to the relative position between the two points, not the absolute coordinates of the point.

(2) Direct return: The system takes the coordinate value of the base point as the relative X, Y, z displacement value. In this case, the coordinates of the base point determine the displacement vector (that is, the distance between the origin and the base), so the basis points can not be arbitrarily determined.