Подумал, что вам может понравиться быстрый пример создания «выделения резинкой». Щелкните и перетащите форму левой кнопкой мыши:
Артефакты взяты с моего устройства записи экрана, на самом деле он рисовался плавно, не оставляя линий:
введите описание изображения здесь
Код:
Public Class Form1
Private ptA, ptB As Point
Private count As Integer = 0
Private firstBoxDrawn As Boolean = False
Private Sub Form1_MouseDown(sender As Object, e As MouseEventArgs) Handles Me.MouseDown
If e.Button = MouseButtons.Left Then
ptA = Me.PointToScreen(New Point(e.X, e.Y))
ptB = ptA
firstBoxDrawn = False
End If
End Sub
Private Sub Form1_MouseMove(sender As Object, e As MouseEventArgs) Handles Me.MouseMove
If e.Button = MouseButtons.Left Then
If firstBoxDrawn Then
' erase the previous box by drawing it again
ControlPaint.DrawReversibleFrame(RectangleFromPoints(ptA, ptB), Color.Black, FrameStyle.Dashed)
End If
ptB = Me.PointToScreen(New Point(e.X, e.Y))
' draw the new box
ControlPaint.DrawReversibleFrame(RectangleFromPoints(ptA, ptB), Color.Black, FrameStyle.Dashed)
firstBoxDrawn = True
End If
End Sub
Private Sub Form1_MouseUp(sender As Object, e As MouseEventArgs) Handles Me.MouseUp
If e.Button = MouseButtons.Left Then
' erase the box
ControlPaint.DrawReversibleFrame(RectangleFromPoints(ptA, ptB), Color.Black, FrameStyle.Dashed)
CreateButton(Me.PointToClient(ptA), Me.PointToClient(ptB))
End If
End Sub
Private Sub CreateButton(ByVal ptA As Point, ByVal ptB As Point)
Dim btn As New Button
btn.Text = "X"
btn.Bounds = RectangleFromPoints(ptA, ptB)
Me.Controls.Add(btn)
End Sub
Private Function RectangleFromPoints(ByVal ptA As Point, ByVal ptB As Point) As Rectangle
Dim pt As New Point(Math.Min(ptA.X, ptB.X), Math.Min(ptA.Y, ptB.Y))
Dim sz As New Size(Math.Abs(ptA.X - ptB.X) + 1, Math.Abs(ptA.Y - ptB.Y) + 1)
Return New Rectangle(pt, sz)
End Function
End Class