Dim a(1 To 100) As Integer, n As Integer

 Private Sub Form_Load()

'本过程从数据库中读取n个IP地址区间数据，并依次存入数组a(1)、…、a(2*n)中

'对能通过过滤的IP区间按区间起始端点升序排序

'代码略

End Sub

Private Sub Cmd1_Click()

Dim ip As Integer, L As Integer, R As Integer

Dim i As Integer, pos As Integer, f As Boolean

ip = Val(Text1.Text)

L = a(1): R = a(2): i = 3: pos = 1     ‘合并重叠区间

Do While i <= 2 * n - 1

    If Then

      If a(i + 1) > R Then R = a(i + 1)

      Else

        a(2 * pos - 1) = L：a(2 * pos) = R

        pos = pos + 1

        L = a(i)

        R = a(i + 1)

      End If

Loop

    a(2 * pos - 1) = L: a(2 * pos) = R           '依次输出排序合并后的区间数据，代码略

    If  Then       '判断请求的 IP 地址

        Label4.Caption = "IP 需过滤"

    Else

        i = 1: f = False

Do While i <= pos And Not f

    If  Then

      i = i + 1

    Else

      Label4.Caption = "IP 不需过滤" f = True

    End If

Loop

  If f = False Then Label4.Caption = "IP 需过滤"

  End If

End Sub