主题：[求助]如何检查地块坐标是否有重叠部分？(搞定）

各位老师，现有一难题：如图，有A、B两块土地，以经纬度形式标注四个角，

这四组数字将能确定一片地块，用什么方法能够检查出A、B两个地块是否出

现重叠或有部分重叠？我都想了一天了，请各位出手帮忙！

也可能是这样的地块

如果是矩形还好做一些，问题地块可能是不规则的四边形.

老大今天这么早啊，我去搜相交了。

搜到了一段VB代码，哪位帮我翻译一下，谢谢！

Private Sub Command1_Click()
Dim X1 As Long, Y1 As Long, X2 As Long, Y2 As Long
Dim A1 As Long, B1 As Long, A2 As Long, B2 As Long
Dim a As Long, b As Long
X1 = Line1.X1: X2 = Line1.X2: Y1 = Line1.Y1: Y2 = Line1.Y2
A1 = Line2.X1: A2 = Line2.X2: B1 = Line2.Y1: B2 = Line2.Y2
a = F(X1, Y1, X2, Y2, A1, B1)
b = F(X1, Y1, X2, Y2, A2, B2)
If a * b = 0 Then
Print "两直线有交叉。"
ElseIf a * b > 0 Then
Print "两直线没有交叉。"
Else
a = F(A1, B1, A2, B2, X1, Y1)
b = F(A1, B1, A2, B2, X2, Y2)
If a * b <= 0 Then
Print "两直线有交叉。"
Else
Print "两直线没有交叉。"
End If
End If
End Sub

Private Function F(ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long, ByVal X As Long, ByVal Y As Long) As Long
Dim K As Long
K = (Y2 - Y1) * X - (X2 - X1) * Y + X2 * Y1 - X1 * Y2
F = Sgn(K)
End Function

多谢程版，我是在网上找到的两条线段是否相交的计算方法，不懂其中道理，但经过一下午的测试，感觉还是可以用的。

下载信息  [文件大小：   下载次数： ]

点击浏览该文件:土地登记.foxdb