如何检查椭圆形是否触及任何其他椭圆形VB

Question

因此，我正在学习visual basic，并且试图制作一个移动椭圆形的计时器，并检查是否触及任何其他椭圆形，它会将一个整数。所以我有这个代码，这有效，但我想知道如果我可以缩短它。如果你可以解释你的代码，因为我很新，这将是伟大的！提前致谢！

Private Sub Timer4_Tick(sender As System.Object, e As System.EventArgs) Handles Timer4.Tick, Timer4.Tick 
    Dim Pos As Integer 
    If bb.Bounds.IntersectsWith(OvalShape1.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape2.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape3.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape4.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape5.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape6.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape7.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape8.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape9.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape10.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape11.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape12.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape13.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape14.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape15.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape16.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape17.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape18.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape19.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape20.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape21.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape22.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape23.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape24.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape25.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    If bb.Bounds.IntersectsWith(OvalShape26.Bounds) Then 
     Pos = -20 
    Else 
     Pos = 20 
    End If 
    bb.Top -= Pos 
End Sub 

Answer 1

你应该重构重码出到一个方法，并为您的常量，以便更好地解释他们的意思是：

Shared Function GetIntersection(Shape first, Shape second) 
    Const IntersectionValue = -20 
    Const NonIntersectionValue = 20 

    If first.Bounds.IntersectsWith(second.Bounds) Then 
     return IntersectionValue 
    Else 
     return NonIntersectionValue 
    End If 
End Function 

然后你会这样称呼它：

Dim Pos As Integer = GetIntersection(bb, OvalShape1) 

这是良好软件设计的重要原则之一：Don't Repeat Yourself (D.R.Y)。

尽管你的代码存在问题 - 不管你是按照你的方式还是按照我的建议，你都不会对值做任何事情 - 你用每个值覆盖值随后的操作。例如：

If bb.Bounds.IntersectsWith(OvalShape1.Bounds) Then 
    Pos = -20 
Else 
    Pos = 20 
End If 

' you should at least do something with `Pos` assigned in the 
' above if-else block before you overwrite it with the following if-else: 

If bb.Bounds.IntersectsWith(OvalShape2.Bounds) Then 
    Pos = -20 
Else 
    Pos = 20 
End If 

事情是这样的，但是，它只是以往任何时候都采取价值的Pos的最后的if-else块

If bb.Bounds.IntersectsWith(OvalShape26.Bounds) Then '... 

，那么什么是点在它之前的其他块？它们只是浪费在头顶上。