《在VB中创建独立控制界面的 ActiveX Dll 部件》2000/02/01 的老帖找到还真不容易!
由 Microsoft 所提出的部件对象模型 (COM) ,包括 Automation 和 ActiveX 规范。通过 ActiveX
部件技术可以把已创建的基于对象的部件组合起来,这些部件可以通过许多不同的工具来创建。应用"部
件软件开发"方法有代码重用、模块功能分明等许多好处。下面以创建独立的界面控制 ActiveX Dll 部
件为题,做进一步分析:
以下两个 ActiveX Dll 部件均实现了"在部件内部响应事件",即:在类模块内引用带事件的对象,以
及在程序运行阶段动态添加控件(实现的技术细节可参阅《MSDN》)。
例2:在 Delphi 提供了 Splitter 控件,轻而易举就实现了窗体界面的分割视图,而在 VB 中要实现这一
功能则要编写大量代码。
可参阅 VB 6 的"树状视图列表视图拆分条"控件集或"VB 应用程序向导 --> 资源管理器样式"代码,
现将其加工移植为 ActiveX Dll 部件:
创建ActiveX Dll(命名为:EasyViews)工程,并在类模块(命名为:SplitView)
添加如下代码:
Option Explicit
Dim mbMoving As Boolean
Const iError = 120
Const iErrorXY = 150
Const SplitterHW = 80
Dim LeftCtl As Control
Dim RightCtl As Control
Dim TopCtl As Control
Dim BottomCtl As Control
Dim WithEvents ImgSplitterH As Image
Dim WithEvents ImgSplitterV As Image
Dim PictureH As PictureBox
Dim PictureV As PictureBox
Dim WithEvents FormX As Form
Dim iMinWidth As Integer
Dim iMinHeight As Integer
Dim iLeftMargin As Integer
Dim iRightMargin As Integer
Dim iTopMargin As Integer
Dim iBottomMargin As Integer
Public Property Get LeftMargin() As Integer
LeftMargin = iLeftMargin
End Property
Public Property Let LeftMargin(ByVal vNewValue As Integer)
iLeftMargin = vNewValue
End Property
Public Property Get RightMargin() As Integer
RightMargin = iRightMargin
End Property
Public Property Let RightMargin(ByVal vNewValue As Integer)
iRightMargin = vNewValue
End Property
Public Property Get TopMargin() As Integer
TopMargin = iTopMargin
End Property
Public Property Let TopMargin(ByVal vNewValue As Integer)
iTopMargin = vNewValue
End Property
Public Property Get BottomMargin() As Integer
BottomMargin = iBottomMargin
End Property
Public Property Let BottomMargin(ByVal vNewValue As Integer)
iBottomMargin = vNewValue
End Property
Public Property Get MinWidth() As Integer
MinWidth = iMinWidth
End Property
Public Property Let MinWidth(ByVal vNewValue As Integer)
iMinWidth = vNewValue
End Property
Public Property Get MinHeight() As Integer
MinHeight = iMinHeight
End Property
Public Property Let MinHeight(ByVal vNewValue As Integer)
iMinHeight = vNewValue
End Property
Private Sub FormX_Load()
Dim temp As String
temp = "DynamicImageH"
On Error GoTo ErrorHandler
FormX.Controls.Add "VB.Image", temp, FormX
On Error GoTo 0
With FormX.Controls.Item(temp)
.Visible = True
End With
Set ImgSplitterH = FormX.Controls.Item(temp)
ImgSplitterH.MousePointer = 7 'ccsizeEW
temp = "DynamicImageV"
On Error GoTo ErrorHandler
FormX.Controls.Add "VB.Image", temp, FormX
On Error GoTo 0
With FormX.Controls.Item(temp)
.Visible = True
End With
Set ImgSplitterV = FormX.Controls.Item(temp)
ImgSplitterV.MousePointer = 9 'cc2sizeNS
temp = "DynamicPictureH"
On Error GoTo ErrorHandler
FormX.Controls.Add "VB.PictureBox", temp, FormX
On Error GoTo 0
Set PictureH = FormX.Controls.Item(temp)
PictureH.BorderStyle = 0
PictureH.BackColor = vbBlack
temp = "DynamicPictureV"
On Error GoTo ErrorHandler
FormX.Controls.Add "VB.PictureBox", temp, FormX
On Error GoTo 0
Set PictureV = FormX.Controls.Item(temp)
PictureV.BorderStyle = 0
PictureV.BackColor = vbBlack
LeftCtl.Move LeftMargin, TopMargin
ImgSplitterV.Move LeftCtl.Left + LeftCtl.Width, LeftCtl.Top, SplitterHW, LeftCtl.Height
RightCtl.Move ImgSplitterV.Left + SplitterHW, LeftCtl.Top
RightCtl.Height = LeftCtl.Height
ImgSplitterH.Move LeftCtl.Left, LeftCtl.Top + LeftCtl.Height, FormX.Width - LeftMargin - RightMargin, SplitterHW
BottomCtl.Move LeftCtl.Left, LeftCtl.Top + LeftCtl.Height + SplitterHW 'LeftCtl.Height
Exit Sub
ErrorHandler:
temp = temp & "X"
Resume
End Sub
Public Sub Create(LeftCtlX As Object, RightCtlX As Object, BottomCtlX As Object)
Set LeftCtl = LeftCtlX
Set RightCtl = RightCtlX
'Set TopCtl = TopCtlX
Set BottomCtl = BottomCtlX
Set FormX = LeftCtlX.Container
FormX_Load
End Sub
Private Sub FormX_Resize()
If FormX.WindowState <> vbMinimized Then
If FormX.Width < LeftMargin + RightMargin + SplitterHW + MinWidth + LeftCtl.Width + iErrorXY Then
FormX.Width = LeftMargin + RightMargin + SplitterHW + MinWidth + LeftCtl.Width + iErrorXY
End If
If FormX.Height < TopMargin + BottomMargin + SplitterHW + MinHeight + LeftCtl.Height + iErrorXY + iErrorXY + iErrorXY + 6 Then
FormX.Height = TopMargin + BottomMargin + SplitterHW + MinHeight + LeftCtl.Height + iErrorXY + iErrorXY + iErrorXY + 6
End If
RightCtl.Width = FormX.Width - LeftCtl.Width - SplitterHW - LeftMargin - RightMargin - iErrorXY
ImgSplitterH.Width = FormX.Width - LeftMargin - RightMargin - iErrorXY
BottomCtl.Width = ImgSplitterH.Width
BottomCtl.Height = FormX.Height - ImgSplitterH.Top - BottomMargin - SplitterHW - 405
End If
End Sub
Private Sub ImgSplitterH_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
With ImgSplitterH
PictureH.Move .Left - 10, .Top, .Width + 30, .Height / 2
End With
PictureH.Visible = True
mbMoving = True
End Sub
Private Sub ImgSplitterH_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Button = vbLeftButton Then
If mbMoving Then
If Y + ImgSplitterH.Top < LeftCtl.Top + MinHeight Then
PictureH.Top = LeftCtl.Top + MinHeight
ElseIf Y + ImgSplitterH.Top > FormX.Height - BottomMargin - SplitterHW - MinHeight - iErrorXY - iErrorXY - iErrorXY Then
PictureH.Top = FormX.Height - BottomMargin - SplitterHW - MinHeight - iErrorXY - iErrorXY - iErrorXY
Else
PictureH.Top = Y + ImgSplitterH.Top
End If
End If
End If
End Sub
Private Sub ImgSplitterH_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)
LeftCtl.Height = PictureH.Top - LeftCtl.Top
ImgSplitterV.Height = LeftCtl.Height
RightCtl.Height = LeftCtl.Height
ImgSplitterH.Top = PictureH.Top
BottomCtl.Height = FormX.Height - ImgSplitterH.Top - BottomMargin - SplitterHW - 400 - 5
BottomCtl.Top = PictureH.Top + SplitterHW
PictureH.Visible = False
mbMoving = False
End Sub
Private Sub ImgSplitterV_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
PictureV.Visible = True
With ImgSplitterV
PictureV.Move .Left, .Top - 10, .Width / 2, .Height
End With
mbMoving = True
End Sub
Private Sub ImgSplitterV_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Button = vbLeftButton Then
If mbMoving Then
If X + ImgSplitterV.Left < LeftCtl.Left + MinWidth Then
PictureV.Left = LeftCtl.Left + MinWidth
ElseIf X + ImgSplitterV.Left > FormX.Width - SplitterHW - RightMargin - MinWidth - iErrorXY Then
PictureV.Left = FormX.Width - SplitterHW - RightMargin - MinWidth - iErrorXY
Else
PictureV.Left = X + ImgSplitterV.Left
End If
End If
PictureV.Height = LeftCtl.Height
End If
End Sub
Private Sub ImgSplitterV_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)
ImgSplitterV.Left = PictureV.Left
LeftCtl.Width = PictureV.Left - LeftCtl.Left
RightCtl.Width = FormX.Width - LeftCtl.Width - SplitterHW - LeftMargin - RightMargin - iErrorXY '- iError - 200
RightCtl.Left = PictureV.Left + SplitterHW
PictureV.Visible = False
mbMoving = False
End Sub
至此该部件创建完成。
接下来创建标准工程,并在窗体上绘制任意三个控件,如: TreeView、ListView、DataGrid,并编写
如下代码测试 EasyViews 部件的类 SplitView:
Option Explicit
Dim x As New EasyViews.SplitView
Private Sub Form_Load()
'...
x.TopMargin = 500 ' Toolbar1.Height + 100
x.LeftMargin = 1000
x.RightMargin = 1000
x.BottomMargin = 500 'StatusBar1.Height
x.MinHeight = 1000
x.MinWidth = 1200
x.Create TreeView1, ListView1, DataGrid1
'...
End Sub
例1:使用过 Delphi 和 PB 的人应该知道,她们的 Form 和 Window 不需编程,即可实现滚动窗口。而在
VB 中要实现滚动窗口则需要编写一些代码了,可参阅 MSDN:
《Scroll Bar 控件方案:创建可滚动的图形视口》,现将其加工移植为 ActiveX Dll
部件:
创建 ActiveX Dll(命名为: EasyViews )工程,并在类模块 (命名为:ScrollView) 中添加如下
代码:
Option Explicit
Dim Picture1 As PictureBox
Dim Picture2 As PictureBox
Dim Picture3 As PictureBox
Dim WithEvents HScroll1 As HScrollBar
Dim WithEvents VScroll1 As VScrollBar
Dim WithEvents FormX As Form
Dim iWidth As Integer
Dim iHeight As Integer
Dim iLeft As Integer
Dim iTop As Integer
Dim iLeftMargin As Integer
Dim iRightMargin As Integer
Dim iTopMargin As Integer
Dim iBottomMargin As Integer
Dim bAlignForm As Boolean
Const iErrorXY = 135
Const dXY = 60
Public Sub Create(PictureBox As Object, Optional bAlignFormX As Boolean = True)
Set Picture2 = PictureBox
Set FormX = PictureBox.Container
bAlignForm = bAlignFormX
FormX_Load
End Sub
Private Sub FormX_Load()
Dim temp As String
temp = "DynamicPicture1"
On Error GoTo ErrorHandler
FormX.Controls.Add "VB.PictureBox", temp, FormX
On Error GoTo 0
With FormX.Controls.Item(temp)
.Visible = True
End With
Set Picture1 = FormX.Controls.Item(temp)
temp = "DynamicPicture3"
On Error GoTo ErrorHandler
FormX.Controls.Add "VB.PictureBox", temp, FormX
On Error GoTo 0
With FormX.Controls.Item(temp)
.Visible = True
End With
Set Picture3 = FormX.Controls.Item(temp)
temp = "DynamicHScroll1"
On Error GoTo ErrorHandler
FormX.Controls.Add "VB.HScrollBar", temp ', FormX
On Error GoTo 0
With FormX.Controls.Item(temp)
.Visible = True
End With
Set HScroll1 = FormX.Controls.Item(temp)
temp = "DynamicHScroll1"
On Error GoTo ErrorHandler
FormX.Controls.Add "VB.VScrollBar", temp ', FormX
With FormX.Controls.Item(temp)
.Visible = True
End With
Set VScroll1 = FormX.Controls.Item(temp)
HScroll1.TabStop = False
VScroll1.TabStop = False
Set Picture1.Container = Picture3
Set HScroll1.Container = Picture3
Set VScroll1.Container = Picture3
Set Picture2.Container = Picture1
'Picture3.BorderStyle = 0
Picture1.BorderStyle = 0
Picture2.BorderStyle = 0
If Not bAlignForm Then
Picture3.Move Left, Top, Width, Height
HScroll1.Move 0, Picture3.Height - HScroll1.Height - dXY, Picture3.Width - VScroll1.Width - dXY
VScroll1.Move Picture3.Width - VScroll1.Width - dXY, 0, VScroll1.Width, Picture3.Height - HScroll1.Height - dXY
Picture1.Move 0, 0, Picture3.Width - VScroll1.Width - dXY, Picture3.Height - HScroll1.Height - dXY
Picture2.Move 0, 0
HScroll1.LargeChange = HScroll1.Max / 5
VScroll1.LargeChange = VScroll1.Max / 5
If Picture1.Height >= Picture2.Height Then
HScroll1.Width = Picture3.Width - dXY
Picture1.Width = Picture3.Width - dXY
End If
If Picture1.Width >= Picture2.Width Then
VScroll1.Height = Picture3.Height - dXY
Picture1.Height = Picture3.Height - dXY
End If
HScroll1.Max = Picture2.Width - Picture1.Width '+ 10 '+ dXY
VScroll1.Max = Picture2.Height - Picture1.Height ' + 10 '+ dXY
HScroll1.SmallChange = 100
VScroll1.SmallChange = 100
HScroll1.Visible = (Picture1.Width < Picture2.Width)
VScroll1.Visible = (Picture1.Height < Picture2.Height)
End If
Exit Sub
ErrorHandler:
temp = temp & "X"
Resume
End Sub
Private Sub FormX_Resize()
On Error Resume Next
If bAlignForm Then
Picture3.Move LeftMargin, TopMargin, FormX.Width - LeftMargin - RightMargin - iErrorXY, FormX.Height - TopMargin - BottomMargin - iErrorXY - iErrorXY - iErrorXY
HScroll1.Move 0, Picture3.Height - HScroll1.Height - dXY, Picture3.Width - VScroll1.Width - dXY
VScroll1.Move Picture3.Width - VScroll1.Width - dXY, 0, VScroll1.Width, Picture3.Height - HScroll1.Height - dXY
Picture1.Move 0, 0, Picture3.Width - VScroll1.Width - dXY, Picture3.Height - HScroll1.Height - dXY
Picture2.Move 0, 0
HScroll1.LargeChange = HScroll1.Max / 5
VScroll1.LargeChange = VScroll1.Max / 5
If Picture1.Height >= Picture2.Height Then
HScroll1.Width = Picture3.Width - dXY
Picture1.Width = Picture3.Width - dXY
End If
If Picture1.Width >= Picture2.Width Then
VScroll1.Height = Picture3.Height - dXY
Picture1.Height = Picture3.Height - dXY
End If
HScroll1.Max = Picture2.Width - Picture1.Width ' + dXY
VScroll1.Max = Picture2.Height - Picture1.Height ' + dXY
HScroll1.SmallChange = 100
VScroll1.SmallChange = 100
HScroll1.Visible = (Picture1.Width < Picture2.Width)
VScroll1.Visible = (Picture1.Height < Picture2.Height)
End If
End Sub
Private Sub HScroll1_Change()
Picture2.Left = -HScroll1.Value
End Sub
Private Sub VScroll1_Change()
Picture2.Top = -VScroll1.Value
End Sub
Public Property Get Width() As Integer
Width = iWidth
End Property
Public Property Let Width(ByVal vNewValue As Integer)
iWidth = vNewValue
End Property
Public Property Get Height() As Integer
Height = iHeight
End Property
Public Property Let Height(ByVal vNewValue As Integer)
iHeight = vNewValue
End Property
Public Property Get Left() As Integer
Left = iLeft
End Property
Public Property Let Left(ByVal vNewValue As Integer)
iLeft = vNewValue
End Property
Public Property Get Top() As Integer
Top = iTop
End Property
Public Property Let Top(ByVal vNewValue As Integer)
iTop = vNewValue
End Property
Public Property Get LeftMargin() As Integer
LeftMargin = iLeftMargin
End Property
Public Property Let LeftMargin(ByVal vNewValue As Integer)
iLeftMargin = vNewValue
End Property
Public Property Get RightMargin() As Integer
RightMargin = iRightMargin
End Property
Public Property Let RightMargin(ByVal vNewValue As Integer)
iRightMargin = vNewValue
End Property
Public Property Get TopMargin() As Integer
TopMargin = iTopMargin
End Property
Public Property Let TopMargin(ByVal vNewValue As Integer)
iTopMargin = vNewValue
End Property
Public Property Get BottomMargin() As Integer
BottomMargin = iBottomMargin
End Property
Public Property Let BottomMargin(ByVal vNewValue As Integer)
iBottomMargin = vNewValue
End Property
至此该部件创建完成。
接下来创建标准工程,并在窗体上绘制一 PictureBox(Picture1) 控件,再绘制一定数量的各种控件
在该 PictureBox 控件内,并编写如下代码测试 EasyViews 部件的类 ScrollView :
Option Explicit
Dim x As New EasyViews.ScrollView
Dim y As New EasyViews.ScrollView
Private Sub Form_Load()
'...
x.Left = 1000
x.Top = 200
x.Height = 3000
x.Width = 4000
x.TopMargin = 3000
x.LeftMargin = 500
x.RightMargin = 500
x.BottomMargin = 600
x.Create Picture2 ', False
y.Left = 2000
y.Top = 300
y.Height = 2500
y.Width = 4000
'y.TopMargin = 1000
y.LeftMargin = 1000
y.RightMargin = 1000
y.BottomMargin = 4000
y.Create Picture1, False
'...
End Sub
该方案使调用部件的主程序代码简洁明了,使实现界面控制的"代码部件"与实现其它功能的代码分离,
界限分明、一目了然。
