IntersectsWith就像 BigFunger 已经提到的那样工作。但是另外你应该检查一个矩形是否包含另一个矩形(intersectsWith 只检查相交)。
一个演示它的小样本形式:
Public Class SelectionRectangle
Private first As Point
Private allRectangles As New List(Of RectangleF)
Private Sub form_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs) Handles Me.MouseDown
first = New Point(e.X, e.Y)
End Sub
Private Sub form_MouseUp(ByVal sender As Object, ByVal e As MouseEventArgs) Handles Me.MouseUp
Dim p As New Pen(Brushes.Black, 2)
Dim g As Graphics
Dim second As New Point(e.X, e.Y)
Dim x, y, w, h As Int32
x = DirectCast(IIf(first.X > second.X, second.X, first.X), Int32)
y = DirectCast(IIf(first.Y > second.Y, second.Y, first.Y), Int32)
w = Math.Abs(second.X - first.X)
h = Math.Abs(second.Y - first.Y)
Dim nextRec As New RectangleF(x, y, w, h)
Dim intersects As Boolean = False
For Each rec As RectangleF In allRectangles
If rec.Contains(nextRec) OrElse rec.IntersectsWith(nextRec) Then
intersects = True
Exit For
End If
Next
If Not intersects Then
p.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot
g = Me.CreateGraphics()
g.DrawLine(p, first.X, first.Y, second.X, first.Y)
g.DrawLine(p, second.X, second.Y, first.X, second.Y)
g.DrawLine(p, first.X, first.Y, first.X, second.Y)
g.DrawLine(p, second.X, second.Y, second.X, first.Y)
allRectangles.Add(nextRec)
Else
Beep()
End If
End Sub
End Class
更新:将此代码更改为 1.first 检查两个方向和 2. 对您来说更重要的是:还检查一个矩形是否不仅与另一个相交,而且是否包含另一个矩形。