本示例构建了一个 ActiveX 控件，允许用户在运行时移动和调整控件的大小。它会自动调整它包含的控件的大小以适应。

UserControl 在其右下角包含一个名为 Corner 的小图片框。该控件跟踪其 Mo​​useDown、MouseMove 和 MouseUp 事件。当您拖动该控件时，以下代码会调整 UserControl 的大小，将 Corner 放回右下角，并调整包含的控件的大小以适合。

Option Explicit'Default Property Values:
Const m_def_Draggable = True
Const m_def_MinWidth = 240
Const m_def_MaxWidth = 100000
Const m_def_MinHeight = 240
Const m_def_MaxHeight = 100000
Const m_def_HandleSize = 45
'Property Variables:
Dim m_Draggable As Boolean
Dim m_MinWidth As Long
Dim m_MaxWidth As Long
Dim m_MinHeight As Long
Dim m_MaxHeight As Long
Dim m_HandleSize As LongDim Resizing As Boolean
Dim Moving As Boolean
Dim StartX As Single
Dim StartY As Single' *********************************************
' Start resizing the control.
' *********************************************
Private Sub Corner_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)If Not Draggable Then Exit SubResizing = TrueStartX = XStartY = Y
End Sub' *********************************************
' Resize the control.
' *********************************************
Private Sub Corner_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
Dim dw As Single
Dim dh As Single
Dim wid As Single
Dim hgt As Single
Dim w As Single
Dim h As Single' Do nothing unless we're resizing.If Not Resizing Then Exit Subdw = X - StartXdh = Y - StartYIf dw = 0 And dh = 0 Then Exit Subwid = Width + dw' Make sure we will fit on the form.w = ScaleX(wid, ScaleMode, Parent.ScaleMode)If w > Parent.ScaleWidth - Extender.Left Thenw = Parent.ScaleWidth - Extender.Leftwid = ScaleX(w, Parent.ScaleMode, ScaleMode)End If' Stay between MinWidth and MaxWidth.If wid < m_MinWidth Then wid = m_MinWidthIf wid > m_MaxWidth Then wid = m_MaxWidthhgt = Height + dh' Make sure we will fit on the form.h = ScaleX(hgt, ScaleMode, Parent.ScaleMode)If h > Parent.ScaleHeight - Extender.Top Thenh = Parent.ScaleHeight - Extender.Tophgt = ScaleY(h, Parent.ScaleMode, ScaleMode)End If' Stay between MinHeight and MaxHeight.If hgt < m_MinHeight Then hgt = m_MinHeightIf hgt > m_MaxHeight Then hgt = m_MaxHeightSize wid, hgt
End Sub
' *********************************************
' Stop resizing the control.
' *********************************************
Private Sub Corner_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)Resizing = False
End Sub

UserControl 也在其自己的表面上跟踪 MouseDown、MouseMove 和 MouseUp 事件。当您在 UserControl 上单击并拖动时，代码会确定该控件的位置并调用 Extender.Move 以适当地移动 UserControl。

该控件还包括在注册表中保存和恢复大小和位置的例程，因此程序可以轻松地在程序运行之间保持其大小和位置。