组织新的发票号码

增加发票号并保存其价值是一项常见任务。使用 CustomDocumentProperties(CDP) 是在同一工作簿中以相对安全的方式存储此类数字的好方法，但避免仅在未受保护的工作表中显示相关的单元格值。

附加提示：

或者，你也可以在隐藏的工作表或甚至所谓的非常隐藏的工作表中输入值（请参阅使用 xlVeryHidden 表 。当然，也可以将数据保存到外部文件（例如 ini 文件，csv 或任何其他类型）或者注册表。

示例内容 ：

以下示例显示

• 函数 NextInvoiceNo 设置并返回下一个发票号，
• 一个过程 DeleteInvoiceNo，它完全删除发票 CDP，以及
• 一个程序 showAllCDPs 列出了所有名称的完整 CDP 集合。不使用 VBA，你也可以通过工作簿的信息列出它们：信息| 属性[DropDown：] | 高级属性| 习惯

你可以通过调用上面提到的函数来获取并设置下一个发票号（最后一个加一个），返回一个字符串值以便于添加前缀。InvoiceNo 在所有过程中隐式用作 CDP 名称。

Dim sNumber As String
sNumber = NextInvoiceNo ()

示例代码：

Option Explicit

Sub Test()
  Dim sNumber As String
  sNumber = NextInvoiceNo()
  MsgBox "New Invoice No: " & sNumber, vbInformation, "New Invoice Number"
End Sub

Function NextInvoiceNo() As String
' Purpose: a) Set Custom Document Property (CDP) "InvoiceNo" if not yet existing
'          b) Increment CDP value and return new value as string
' Declarations
  Dim prop As Object
  Dim ret  As String
  Dim wb   As Workbook
' Set workbook and CDPs
  Set wb = ThisWorkbook
  Set prop = wb.CustomDocumentProperties

  ' -------------------------------------------------------
  ' Generate new CDP "InvoiceNo" if not yet existing
  ' -------------------------------------------------------
    If Not CDPExists("InvoiceNo") Then
    '  set temporary starting value "0"
       prop.Add "InvoiceNo", False, msoPropertyTypeString, "0"
    End If

  ' --------------------------------------------------------
  ' Increment invoice no and return function value as string
  ' --------------------------------------------------------
       ret = Format(Val(prop("InvoiceNo")) + 1, "0")
  ' a) Set CDP "InvoiceNo" = ret
       prop("InvoiceNo").value = ret
  ' b) Return function value 
       NextInvoiceNo = ret
End Function

Private Function CDPExists(sCDPName As String) As Boolean
' Purpose: return True if custom document property (CDP) exists
' Method: loop thru CustomDocumentProperties collection and check if name parameter exists
' Site: cf. http://stackoverflow.com/questions/23917977/alternatives-to-public-variables-in-vba/23918236#23918236
' vgl.: https://answers.microsoft.com/en-us/msoffice/forum/msoffice_word-mso_other/using-customdocumentproperties-with-vba/91ef15eb-b089-4c9b-a8a7-1685d073fb9f
' Declarations
  Dim cdp As Variant      ' element of CustomDocumentProperties Collection
  Dim boo As Boolean      ' boolean value showing element exists
  For Each cdp In ThisWorkbook.CustomDocumentProperties
    If LCase(cdp.Name) = LCase(sCDPName) Then
       boo = True      ' heureka
       Exit For        ' exit loop
    End If
  Next
  CDPExists = boo          ' return value to function
End Function

Sub DeleteInvoiceNo()
' Declarations
  Dim wb     As Workbook
  Dim prop   As Object
' Set workbook and CDPs
  Set wb = ThisWorkbook
  Set prop = wb.CustomDocumentProperties

' ----------------------
' Delete CDP "InvoiceNo"
' ----------------------
 If CDPExists("InvoiceNo") Then
    prop("InvoiceNo").Delete
 End If

结束子

Sub showAllCDPs()
' Purpose: Show all CustomDocumentProperties (CDP) and values (if set)
' Declarations
  Dim wb      As Workbook
  Dim cdp     As Object

  Dim i       As Integer
  Dim maxi   As Integer
  Dim s       As String
' Set workbook and CDPs
  Set wb = ThisWorkbook
  Set cdp = wb.CustomDocumentProperties
' Loop thru CDP getting name and value
  maxi = cdp.Count
  For i = 1 To maxi
    On Error Resume Next    ' necessary in case of unset value
    s = s & Chr(i + 96) & ") " & _
            cdp(i).Name & "=" & cdp(i).value & vbCr
  Next i
' Show result string
  Debug.Print s
End Sub