StartUndoMark Method （ActiveX）

签名

工 务 局：

object.StartUndoMark

对象

类型：文档

此方法适用的对象。

返回值（RetVal）

无返回值。

言论

此方法允许 AutoCAD 设置必要的环境，以便将此调用和调用之间完成的操作视为一组操作。EndUndoMark

例子

工 务 局：

Sub Example_StartUndoMark()
    ' This example creates a series of lines, each with an undo marker
    ' defined for it. After lines are created, you can switch to AutoCAD and type
    ' the Undo command, and only one line at a time will be undone. If StartUndoMark
    ' call is not made, an undo in AutoCAD will undo all the lines at once.
    
    Dim line As AcadLine
    Dim stPnt(0 To 2) As Double
    Dim endPnt(0 To 2) As Double
    stPnt(0) = 1: stPnt(1) = 2: stPnt(2) = 0
    endPnt(0) = 2: stPnt(1) = 1: stPnt(2) = 0
    
    ' Create the lines
    Dim j As Integer
    For j = 0 To 3
        ThisDrawing.StartUndoMark
        Set line = ThisDrawing.ModelSpace.AddLine(stPnt, endPnt)
        stPnt(0) = stPnt(0) + 3
        endPnt(0) = endPnt(0) + 3
        ThisDrawing.EndUndoMark
    Next
    ZoomAll
    
End Sub

Visual LISP：

(vl-load-com)
(defun c:Example_StartUndoMark()
    ;; This example creates a series of lines, each one with an undo marker
    ;; defined for it. After lines are created you can switch to AutoCAD and type
    ;; the Undo command, and only one line at a time will be undone. If StartUndoMark
    ;; call is not made, an undo in AutoCAD will undo all the lines at once.
    (setq acadObj (vlax-get-acad-object))
    (setq doc (vla-get-ActiveDocument acadObj))
    (setq modelSpace (vla-get-ModelSpace doc))  

    (setq stPnt (vlax-3d-point 1 2 0)
          endPnt (vlax-3d-point 2 1 0))  

    ;; Create the lines
    (setq j 0)
    (while (>= 3 j)
        (vla-StartUndoMark doc)
        (setq line (vla-AddLine modelSpace stPnt endPnt))
        (vlax-safearray-put-element (vlax-variant-value stPnt) 0 (+ (vlax-safearray-get-element (vlax-variant-value stPnt) 0) 3))
        (vlax-safearray-put-element (vlax-variant-value endPnt) 0 (+ (vlax-safearray-get-element (vlax-variant-value endPnt) 0) 3))
        (setq j (1+ j))
        (vla-EndUndoMark doc)
    )
    (vla-ZoomAll acadObj)
)