程序代码如下所示：


Public Class Resize

'移动了吗？

Private IsMoving As Boolean = False

'控件最后的宽

Private ctrlLastWidth As Integer = 0

'控件最后的高

Private ctrlLastHeight As Integer = 0

'控件原来的宽

Private ctrlWidth As Integer

'最后的左侧坐标

Private ctrlLastLeft As Integer

'最后的顶部坐标

Private ctrlLastTop As Integer

'控件原来的高

Private ctrlHeight As Integer

'控件的左侧坐标

Private ctrlLeft As Integer

'控件的顶部坐标

Private ctrlTop As Integer

'光标的左侧坐标

Private cursorL As Integer

'光标的顶部坐标

Private cursorT As Integer

Private Htap As Integer

Private Wtap As Integer

Private ctrlIsResizing As Boolean = False

'控件的大小矩形

Private ctrlRectangle As System.Drawing.Rectangle = New System.Drawing.Rectangle()

Private ctrl As Control '操作的控件

Private frm As Form '控件的父亲窗体

'构造函数

Public Sub New(ByVal c As Control, ByVal frm As Form)

ctrl = c

   Me.frm = frm '标题栏和横向滚动条以及边框的宽

   Me.Htap = Me.frm.Height - Me.frm.ClientRectangle.Height'纵向滚动条和边框的宽

   Me.Wtap = Me.frm.Width - Me.frm.ClientRectangle.Width

   AddHandler ctrl.MouseDown, AddressOf MouseDown

   AddHandler ctrl.MouseMove, AddressOf MouseMove

   AddHandler ctrl.MouseUp, AddressOf MouseUp

End Sub


'鼠标按下后的处理

Private Sub MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs)

If frm Is Nothing Then

   Return

End If

   MessageBox.Show(e.Y.ToString)

   MessageBox.Show((Me.ctrl.Height - 10).ToString)

   MessageBox.Show(e.X.ToString)

   MessageBox.Show((Me.ctrl.Width - 10).ToString)

   '设置第一次有效单击的范围

   If e.X < Me.ctrl.Width - 10 OrElse e.Y < Me.ctrl.Height - 10 Then

   Me.IsMoving = True

   '指定要绘制的虚线框的坐标（相对屏幕）

   Me.ctrlLeft = Me.frm.DesktopLocation.X + Me.Wtap + Me.ctrl.Left

   Me.ctrlTop = Me.frm.DesktopLocation.Y + Me.Htap + Me.ctrl.Top

   '光标的位置

   Me.cursorL = Cursor.Position.X

   Me.cursorT = Cursor.Position.Y

   '控件的原来宽与高

   Me.ctrlWidth = Me.ctrl.Width

   Me.ctrlHeight = Me.ctrl.Height

End If



ctrlRectangle.Location = New System.Drawing.Point(Me.ctrlLeft, Me.ctrlTop)

ctrlRectangle.Size = New System.Drawing.Size(ctrlWidth, ctrlHeight)


'绘制框架（矩形大小，背景色，边框风格（这里是虚线框））

ControlPaint.DrawReversibleFrame(ctrlRectangle, Color.Empty, System.Windows.Forms.FrameStyle.Dashed)


End Sub


Private Sub MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs)

If frm Is Nothing Then

   Return

End If


'如果是鼠标左键


If e.Button = MouseButtons.Left Then

If Me.IsMoving Then

   If ctrlLastLeft = 0 Then

   ctrlLastLeft = ctrlLeft

End If


If ctrlLastTop = 0 Then

   ctrlLastTop = ctrlTop

End If


Dim locationX As Integer = (Cursor.Position.X - Me.cursorL + Me.frm.DesktopLocation.X + Me.Wtap + Me.ctrl.Location.X)

Dim locationY As Integer = (Cursor.Position.Y - Me.cursorT + Me.frm.DesktopLocation.Y + Me.Htap + Me.ctrl.Location.Y)

If locationX < Me.frm.DesktopLocation.X + Me.Wtap Then

   locationX = Me.frm.DesktopLocation.X + Me.Wtap


End If



If locationY < Me.frm.DesktopLocation.Y + Me.Htap Then

   locationY = Me.frm.DesktopLocation.Y + Me.Htap

End If


Me.ctrlLeft = locationX

Me.ctrlTop = locationY

ctrlRectangle.Location = New System.Drawing.Point(Me.ctrlLastLeft, Me.ctrlLastTop)

ctrlRectangle.Size = New System.Drawing.Size(ctrlWidth, ctrlHeight)

ControlPaint.DrawReversibleFrame(ctrlRectangle, Color.Empty, System.Windows.Forms.FrameStyle.Dashed)

ctrlLastLeft = ctrlLeft

ctrlLastTop = ctrlTop

ctrlRectangle.Location = New System.Drawing.Point(ctrlLeft, ctrlTop)

ctrlRectangle.Size = New System.Drawing.Size(ctrlWidth, ctrlHeight)

ControlPaint.DrawReversibleFrame(ctrlRectangle, Color.Empty, System.Windows.Forms.FrameStyle.Dashed)

Return

End If



Dim sizeageX As Integer = (Cursor.Position.X - Me.frm.DesktopLocation.X - Me.Wtap - Me.ctrl.Location.X)

Dim sizeageY As Integer = (Cursor.Position.Y - Me.frm.DesktopLocation.Y - Me.Htap - Me.ctrl.Location.Y)

If sizeageX < 2 Then

   sizeageX = 1

End If



If sizeageY < 2 Then

   sizeageY = 1

End If



ctrlWidth = sizeageX

ctrlHeight = sizeageY

If ctrlLastWidth = 0 Then

   ctrlLastWidth = ctrlWidth

End If



If ctrlLastHeight = 0 Then

   ctrlLastHeight = ctrlHeight

End If


If ctrlIsResizing Then

   ctrlRectangle.Location = New System.Drawing.Point(Me.frm.DesktopLocation.X + Me.ctrl.Left + Me.Wtap, Me.frm.DesktopLocation.Y + Me.Htap + Me.ctrl.Top)

   ctrlRectangle.Size = New System.Drawing.Size(ctrlLastWidth, ctrlLastHeight)


End If



ctrlIsResizing = True

ControlPaint.DrawReversibleFrame(ctrlRectangle, Color.Empty, System.Windows.Forms.FrameStyle.Dashed)

ctrlLastWidth = ctrlWidth

ctrlLastHeight = ctrlHeight

ctrlRectangle.Location = New System.Drawing.Point(Me.frm.DesktopLocation.X + Me.Wtap + Me.ctrl.Left, Me.frm.DesktopLocation.Y + Me.Htap + Me.ctrl.Top)

ctrlRectangle.Size = New System.Drawing.Size(ctrlWidth, ctrlHeight)

ControlPaint.DrawReversibleFrame(ctrlRectangle, Color.Empty, System.Windows.Forms.FrameStyle.Dashed)

End If

End Sub



Private Sub MouseUp(ByVal sender As Object, ByVal e As MouseEventArgs)

If frm Is Nothing Then

   Return

End If

ctrlIsResizing = False

If Me.IsMoving Then

   ctrlRectangle.Location = New System.Drawing.Point(Me.ctrlLeft, Me.ctrlTop)

   ctrlRectangle.Size = New System.Drawing.Size(ctrlWidth, ctrlHeight)

   ControlPaint.DrawReversibleFrame(ctrlRectangle, Color.Empty,System.Windows.Forms.FrameStyle.Dashed)

   Me.ctrl.Left = Me.ctrlLeft - Me.frm.DesktopLocation.X - Me.Wtap
  
   Me.ctrl.Top = Me.ctrlTop - Me.frm.DesktopLocation.Y - Me.Htap

   Me.IsMoving = False

   Me.ctrl.Refresh()

   Return

End If


ctrlRectangle.Location = New System.Drawing.Point(Me.frm.DesktopLocation.X + Me.Wtap + Me.ctrl.Left, Me.frm.DesktopLocation.Y + Me.Htap + Me.ctrl.Top)

ctrlRectangle.Size = New System.Drawing.Size(ctrlWidth, ctrlHeight)

ControlPaint.DrawReversibleFrame(ctrlRectangle, Color.Empty, System.Windows.Forms.FrameStyle.Dashed)

   Me.ctrl.Width = ctrlWidth

   Me.ctrl.Height = ctrlHeight

   Me.ctrl.Refresh()


End Sub

End Class