Question

VB调用CAD画图问题

有一个调用VB画图的程序，可是画出的不是多边形，而是有很多直线会交叉 如何解决，望大虾们指点。Private Sub Command1_Click()

Dim XLAPP As Excel.Application
Set XLAPP = New Excel.Application
Set XLAPP = CreateObject("excel.application")

Dim BOOK_JSMJ As Excel.Workbook
Dim SHEET_JSMJ As Excel.Worksheet
Dim X(50), Y(50) As Double

Set BOOK_JSMJ = XLAPP.Workbooks.Open("E:\张三\计算多边形面积")
Set SHEET_JSMJ = BOOK_JSMJ.Worksheets("sheet1")
SHEET_JSMJ.Activate

Dim n As Integer
Dim P1(0 To 2) As Double
Dim P2(0 To 2) As Double
Dim MJ, ZC As Double

'--------------------------------
Dim myDoc As AcadDocument
Dim myMos As AcadModelSpace
Dim myPas As AcadPaperSpace
Dim LINE As AcadLine
Dim TEXT As AcadText

Dim myacadApp As AcadApplication
Set myacadApp = New AcadApplication
Set myacadApp = GetObject(, "AutoCAD.Application")
If Err Then
Err.Clear
Set myacadApp = CreateObject("AutoCAD.Application")
If Err Then
MsgBox Err.Description
Exit Sub
End If
End If

Set myDoc = myacadApp.ActiveDocument
myacadApp.Visible = True

n = Val(Form1.Text1(0).TEXT)
For j = 1 To n + 1 '给各顶点赋值
X(j) = SHEET_JSMJ.Cells(j + 1, 2)
Y(j) = SHEET_JSMJ.Cells(j + 1, 3)
Next
X(n + 1) = X(1): Y(n + 1) = Y(1) '多边形必须是封闭的

MJ = 0: ZC = 0 '循环起点值为零
For j = 1 To 5 '计算多边形面积和周长
MJ = MJ + X(j) * Y(j + 1) - Y(j) * X(j + 1)
ZC = ZC + Sqr((X(j) - X(j + 1)) * (X(j) - X(j + 1)) + _
(Y(j) - Y(j + 1)) * (Y(j) - Y(j + 1)))
Next
MJ = MJ / 2
MJ = Int(MJ * 1000 + 0.5) / 1000
ZC = Int(ZC * 1000 + 0.5) / 1000

Form1.Text1(0) = n
Form1.Text1(1) = MJ
Form1.Text1(2) = ZC
If Form1.Check1.Value = 1 Then '在CAD绘图多边形
For j = 1 To n
P1(0) = Int(X(j))
P1(1) = Int(Y(j))
P1(2) = Int(0)
P2(0) = Int(X(j + 1))
P2(1) = Int(Y(j + 1))
P2(2) = Int(0)
Set LINE = myDoc.ModelSpace.AddLine(P1, P2)
ZoomAll
Next

P2(0) = (X(2) + X(3)) / 2: P2(1) = X(2) - 4
Set TEXT = myDoc.ModelSpace.AddText("S=" & MJ, P2, 3) '标注面积
P2(1) = P2(1) - 4:
Set TEXT = myDoc.ModelSpace.AddText("L=" & ZC, P2, 3) '标注周长
ZoomAll
End If

End Sub

Sub jisuan()
End Sub

老师提示说只需要稍微修改下就可以了，具体位置大概在n = Val(Form1.Text1(0).TEXT)
For j = 1 To n + 1 '给各顶点赋值
之后的内容。

请求大神帮忙啊

具体的EXCEL文件内容
坐标 X Y
D1 20 20
D2 40 20
D3 20 40
D4 40 40
D5 30 50

最好能在此程序上直接修改，谢谢了，回答对的再追加50分

Answer 1

我想是你的Excel数据有问题吧？顺序换一下就成了，把第D3这行放到最后一行，四、五行上移：

坐标 X Y  

D1 20 20

D2 40 20

D3 40 40

D4 30 50

D5 20 40

画出个五边形？对吗？

Answer 2

你没有按多边形各顶点的顺序依次给出坐标，程序画出来的当然会交叉，你用的是VB 什么版本的，VB 6.0程序无法执行，显示的都是错误

Answer 3

使用Thgis软件，再复杂的图形都能轻松、快捷、精确地绘制，面积自动生成。

Answer 4

相关代码已发,请速分.