关于VBA intersectwith函数如何判断是否有交点的问题

 
Private Sub DrawAltitude(ByRef Altitude() As Double)  'VB输出数组要通过ByRef 引用才行，不能直接输出
    ConnectAutoCAD
    '获取交点并写入数组中
    Dim CrossPoint As Variant
    Dim pickedobjs1 As AcadEntity
    Dim pickedobjs2 As AcadEntity
    Dim nLWS, nLS As Integer
    nLWS = CorrLineObj.Count: nLS = GuideLinesObj.Count  '选中的对象个数
    Dim cpnts() As Double        '交点数组
'    Dim Altitude() As Double     '高程数组
    ReDim cpnts(0 To nLWS - 1, 0 To nLS - 1, 2) As Double '定义一个三维动态数组用于存放交点坐标
    ReDim Altitude(0 To nLWS - 1, 0 To nLS - 1, 2) As Double
    Dim i As Integer
    Dim j As Integer
    Dim k As Integer
    Dim textobj As AcadText
    i = 0: j = 0: k = 0
    For Each pickedobjs1 In CorrLineObj
        Thisdrawing.Utility.Prompt vbCrLf & (i + 1) & "/" & CorrLineObj.Count
        pickedobjs1.Highlight (True) '高亮选中的实体
        pickedobjs1.Update
        j = 0
        For Each pickedobjs2 In GuideLinesObj
            pickedobjs1.Highlight (True)  '高亮选中的实体
            pickedobjs1.Update
            CrossPoint = pickedobjs1.IntersectWith(pickedobjs2, acExtendNone) '获取交点
            
            If VarType(CrossPoint)  vbEmpty Then '执行计算
                Thisdrawing.Utility.Prompt vbCrLf & CrossPoint(1)
                Thisdrawing.Utility.Prompt vbCrLf & CrossPoint(0) & "," & CrossPoint(1) & "," & CrossPoint(2)
                cpnts(i, j, 0) = CrossPoint(0)
                cpnts(i, j, 1) = CrossPoint(1)
                cpnts(i, j, 2) = CrossPoint(2) '交点数组
                Altitude(i, j, 0) = CrossPoint(0)
                Altitude(i, j, 1) = CrossPoint(1) - CDbl(HeightBaseP(1)) + HeightBaseVal
                Altitude(i, j, 2) = CrossPoint(2) '高程数组
                '写入高程信息
                textInBasePoint(0) = CrossPoint(0)
                textInBasePoint(2) = CrossPoint(2)
                Set textobj = Thisdrawing.ModelSpace.AddText(CStr(Format(Altitude(i, j, 1), "0.00")), textInBasePoint, 1.5)
                textobj.Rotate textInBasePoint, pi / 2  '旋转90°布置
            End If
                 j = j + 1
        Next pickedobjs2
       i = i + 1
    Next pickedobjs1
    Thisdrawing.Utility.Prompt vbCrLf & "任务已完成！"
End Sub

Sub Example_IntersectWith()
    ' This example creates a line and circle and finds the points at
    ' which they intersect.
    
    ' Create the line
    Dim lineObj As AcadLine
    Dim startPt(0 To 2) As Double
    Dim endPt(0 To 2) As Double
    startPt(0) = 1: startPt(1) = 1: startPt(2) = 0
    endPt(0) = 5: endPt(1) = 5: endPt(2) = 0
    Set lineObj = ThisDrawing.ModelSpace.AddLine(startPt, endPt)
        
    ' Create the circle
    Dim circleObj As AcadCircle
    Dim centerPt(0 To 2) As Double
    Dim radius As Double
    centerPt(0) = 3: centerPt(1) = 3: centerPt(2) = 0
    radius = 1
    Set circleObj = ThisDrawing.ModelSpace.AddCircle(centerPt, radius)
    ZoomAll
      
    ' Find the intersection points between the line and the circle
    Dim intPoints As Variant
    intPoints = lineObj.IntersectWith(circleObj, acExtendNone)
    
    ' Print all the intersection points
    Dim I As Integer, j As Integer, k As Integer
    Dim str As String
    If VarType(intPoints)  vbEmpty Then
        For I = LBound(intPoints) To UBound(intPoints)
            str = "Intersection Point[" & k & "] is: " & intPoints(j) & "," & intPoints(j + 1) & "," & intPoints(j + 2)
            MsgBox str, , "IntersectWith Example"
            str = ""
            I = I + 2
            j = j + 3
            k = k + 1
        Next
    End If
End Sub