两条直线是否相交

这个比较简单,各直线直接取2点 ,计算斜率!只有相等才是平行(这里是在一个平面)

下面是VB代码,计算的是正切 (TAN)

 

Option ExplicitConst xx As Double = 0.0000001Private Sub Command1_Click()    MsgBox IsConnect(Line1, Line2)End Sub

Public Function IsConnect(Line1 As Line, Line2 As Line) As Boolean    IsConnect = False

    Dim Rate1 As Double    Dim Rate2 As Double    If Line1.X2 = Line1.X1 Then        Rate1 = 0    Else        Rate1 = (Line1.Y2 - Line1.Y1) / (Line1.X2 - Line1.X1)    End If

    If Line2.X2 = Line2.X1 Then        Rate2 = 0    Else        Rate2 = (Line2.Y2 - Line2.Y1) / (Line2.X2 - Line2.X1)    End If

    If Abs(Rate1 - Rate2) > xx Then        IsConnect = True    Else        IsConnect = False    End IfEnd Function