test.frm

可以对无限长度的整数进行加、减

VERSION 5.00
Begin VB.Form Test 
   BorderStyle     =   1  'Fixed Single
   Caption         =   "Test"
   ClientHeight    =   3090
   ClientLeft      =   45
   ClientTop       =   435
   ClientWidth     =   4680
   LinkTopic       =   "Form1"
   MaxButton       =   0   'False
   MinButton       =   0   'False
   ScaleHeight     =   3090
   ScaleWidth      =   4680
   StartUpPosition =   2  '屏幕中心
   Begin VB.TextBox Text3 
      Height          =   270
      Left            =   600
      TabIndex        =   5
      Top             =   1080
      Width           =   3855
   End
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   255
      Left            =   1080
      TabIndex        =   2
      Top             =   1800
      Width           =   1935
   End
   Begin VB.TextBox Text2 
      Height          =   270
      Left            =   600
      TabIndex        =   1
      Top             =   600
      Width           =   3855
   End
   Begin VB.TextBox Text1 
      Height          =   270
      Left            =   600
      TabIndex        =   0
      Top             =   120
      Width           =   3855
   End
   Begin VB.Label Label3 
      Caption         =   "基数"
      Height          =   255
      Left            =   120
      TabIndex        =   6
      Top             =   1080
      Width           =   375
   End
   Begin VB.Label Label2 
      Caption         =   "位数"
      Height          =   255
      Left            =   120
      TabIndex        =   4
      Top             =   600
      Width           =   375
   End
   Begin VB.Label Label1 
      Caption         =   "阶乘"
      Height          =   255
      Left            =   120
      TabIndex        =   3
      Top             =   120
      Width           =   495
   End
End
Attribute VB_Name = "Test"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Sub Command1_Click()
    Text1.Text = nj(Val(Text3.Text))
    Text2.Text = Len(Text1.Text)
End Sub
Private Function nj(n As Long) As String
    If n = 1 Then
        nj = "1"
    Else
        nj = Multiply(CStr(n), nj(n - 1))
    End If
End Function