VB4.0提供了一個新功能:Add-Ins，利用這一功能我們就可以把自己的程序加到VB4的系統菜單Add-Ins里去，作為VB的擴展功能。我們設計的程序將具有以下功能：選取窗體上某些控件后，通過菜單選取，使它們大小相同、間距相同、邊緣對齊等等。有了這些功能,我們設計界面時就能節省大量時間,大大提高工作效率。限于篇幅,這里只介紹其中一個功能:使所選取控件從左到右大小相同。理解了這段程序,其它功能就很容易實現了。首先建一個新項目:alignment.mark,不需要任何窗體,在Tools菜單里選Project Options， 將 Project Name設為Exam”,將Start Mode設為Object Application后退出。然后在菜單Ins ert里選取ClassModule,建立一個新類,屬性設置如下:

Name=HSizeAlign;Creatable=False;Public=True 輸入以下程序:

Public VBInstance As Object ’當前所運行的VB
Private TheseControls As Object
Private Control As Onject ’控件對象變量
Private AllHeight As Long
Private AllWidth As Long
Private MinLeft As Long ’標記最左邊界值
Public Sub AfterClick()
MinLeft=99999 ’設一極大初值
Set ThereControls = VBInstance.ActiveProject.Ac - tiveForm.SelectedControlTemplates
For Each Control In TheseControls
If Control.Properties(Left)＜MinLeft Then
AllHeight=Control.Properties(Height)
AllWidth=Control.Properties(Width)
MinLeft=Control.Properties(Left)
End If
Next
For Each Control In TheseControls
Control.Properties(Height)=AllHeight
Control.Properties(Width)=AllWidth
Next
End Sub

再定義一個新類,屬性設置如下:

Name=Alignment;Creatable=True;Public=True
Dim ThisInstance As Object
Dim HSizeAlignMenu As Object
Dim HSizeAlignHandler As New HSizeAlign
Dim HSizeConnectCookie As Long
Sub ConnectA n(VBInstance As Object)
’加入菜單項,進行連接
Set ThisInstance=VBInstance
Set HSizeAlignMenu=ThisInstance.AddinMenu.
MenuItems.Add(HSize Alignment)
Set HSizeAlignHandler.VBInstance=ThisInstance
HSizeConnectCookie=HSizeAlignMenu.ConnectEvents
(HSizeAlignHandler)
End Sub
Sub DisconnectAddIn(Mode As Integer)
’解除連接,刪除菜單項
HSizeAlignMenu.DisconnectEvents HSizeConnect-Cookie
ThisInstance.AddinMenu.MenuItems.Remove HSizeAlignMenu
End Sub
再加入一個Module,輸入以下程序:
Declare Function WritePrivateProfileString Lib
KERNEL(ByVal AppName$,ByVal KeyName$,ByVal keydefault$,ByVal FileName$)
Declare Function GetPrivateProfileString Lib
KERNEL(ByVal AppName$,ByVal KeyName$,ByVal keydefault$,ByVal ReturnString$,By
Val NumBytes As Integer,ByVal FileName$)
’以上說明可用API Text Viewer拷貝
Sub Main()
Dim ReturnString As String
Section$=Add-Ins16
ReturnString=String$(255,Chr$(0))
ErrCode=GetPrivateProfileString(Section$,
Exam.Alignment,NotFound,ReturnString,Len(ReturnString)+1,VB.INI)
If Left(ReturnString,InStr(ReturnString,Chr(0))-1)=NotFoundThen
ErrCode=WritePrivateProfileString%(Section$,Exam.Alignment,0,VB.INI)
End If
End Sub

Exam.Alignment里,Exam”為項目名,Alignment”為與Add-In菜單連接的類名。以上程序編譯運行后,在VB菜單Add-Ins里選取Add-In Manager,將彈出一對話框,選取Exam. Alignment后退出,Add-Ins菜單里就多了一項HSize Alignment;使用時先選取所需排列控件,然后選此菜單項即可。本程序的運行環境為:VB4.0,Windows3.1;486 DX2/66 8M。