可以使用COM技術,在VB中直接操作AutoCAD,創建于VBA功能類似的程序,VB能夠直接打包生成安裝文件,這種形式比VBA更加方便,并且更容易保護自己的程序。VB連接到AutoCAD主要用到CreateObject和GetObject函數,創建或者獲得對ActiveX對象的引用。
連接到AutoCAD之后,就可以使用acadApp對象對AutoCAD進行操作,語法和操作方法與VBA完全一致。
下面這段代碼創建一個繪制樓梯剖面圖的程序。
Dim bcal As Boolean
Dim ptarr1() As Double
Dim ptarr2(19) As Double
Private Sub cmdcal_Click()
Dim objcontrol As Control
For Each objcontrol In Form1.Controls
If TypeOf objcontrol Is TextBox Then
If objcontrol.Text = "" Then
MsgBox "缺少參數,無法計算!", vbCritical
Exit Sub
End If
End If
Next
Dim x0 As Double, y0 As Double
Dim s As Double, t As Double, n As Double
Dim b As Double, h As Double, h0 As Double
x0 = txtptx.Text: y0 = txtpty.Text
s = txtsteph.Text: t = txtstepw.Text: n = txtstepnum.Text
b = txtgriderw.Text: h = txtgriderh.Text: h0 = txtboardt.Text
If h0 >= h Or b > 80 Or s >= t Then
MsgBox "輸入條件不符合要求,請檢查參數的合理性!", vbCritical
Exit Sub
End If
ReDim ptarr1(2 * (2 * n + 2) – 1)
ptarr1(0) = x0 – 100: ptarr1(1) = y0
ptarr1(2) = x0: ptarr1(3) = y0
ptarr1(4) = x0: ptarr1(5) = y0 + s
Dim i As Integer
For i = 6 To 2 * (2 * n + 2) – 3
If i Mod 4 = 2 Then
ptarr1(i) = ptarr1(i – 4) + t
ElseIf i Mod 4 = 3 Then
ptarr1(i) = ptarr1(i – 4) + s
ElseIf i Mod 4 = 0 Then
ptarr1(i) = ptarr1(i – 2)
ElseIf i Mod 4 = 1 Then
ptarr1(i) = ptarr1(i – 2) + s
End If
Next i
ptarr1(2 * (2 * n + 2) – 2) = ptarr1(2 * (2 * n + 2) – 4) + 100
ptarr1(2 * (2 * n + 2) – 1) = ptarr1(2 * (2 * n + 2) – 3)
ptarr2(0) = x0 – 100: ptarr2(1) = y0 – h0
ptarr2(2) = x0 – b: ptarr2(3) = y0 – h0
ptarr2(4) = x0 – b: ptarr2(5) = y0 – h
ptarr2(6) = x0: ptarr2(7) = y0 – h
ptarr2(8) = x0: ptarr2(9) = y0 – h0
ptarr2(10) = x0 + (n – 1) * t: ptarr2(11) = y0 + (n – 1) * s – h0
ptarr2(12) = ptarr1(2 * (2 * n + 2) – 4): ptarr2(13) = ptarr1(2 * (2 * n + 2) – 3) – h
ptarr2(14) = ptarr2(12) + b: ptarr2(15) = ptarr2(13)
ptarr2(16) = ptarr2(14): ptarr2(17) = ptarr2(15) + (h – h0) #p#分頁標題#e#
ptarr2(18) = ptarr1(2 * (2 * n + 2) – 2): ptarr2(19) = ptarr1(2 * (2 * n + 2) – 1) – h0
bcal = True
End Sub
Private Sub cmddraw_Click()
If bcal = False Then
MsgBox "請先進行計算,再進行繪圖!", vbCritical
Exit Sub
End If
On Error Resume Next
Dim acadapp As AcadApplication
Set acadapp = GetObject(, "AutoCAD.Application.16")
If Err Then
Err.Clear
‘MsgBox "sssssssssssss"
‘Set acadapp = CreatObject("AutoCAD.Application.16")
If Err Then
MsgBox Err.Description
Exit Sub
End If
End If
Dim acaddoc As AcadDocument
Set acaddoc = acadapp.ActiveDocument
acaddoc.ModelSpace.AddLightWeightPolyline ptarr1
acaddoc.ModelSpace.AddLightWeightPolyline ptarr2
ZoomAll
acadapp.Visible = True
bcal = False
End Sub
Private Sub cmdexit_Click()
End
End Sub
Private Sub Form_Load()
txtptx.Text = 0
txtpty.Text = 0
txtptz.Text = 0
txtsteph.Text = 20
txtstepw.Text = 40
txtstepnum.Text = 10
txtgriderw.Text = 25
txtgriderh.Text = 45
txtboardt.Text = 15
bcal = False
End Sub
因為VB和AutoCAD之間是通過COM技術連接,這種數據交換對系統資源的消耗很大,同樣的計算在VB運算消耗的時間比在VBA中的運算時間要多5倍以上,在VB中按F5鍵運行程序,可以在Form中對樓梯參數進行設置,就可在CAD中繪制樓梯剖面圖。創建VB程序時要盡可能減少程序和AutoCAD之間的數據交換,所有計算盡量在VB中完成,直接傳遞給AutoCAD計算結果,使CAD可以直接根據結果進行繪圖。在VB中按下F5鍵,單擊繪圖按鈕即可在CAD中看到繪制的樓梯剖面圖。