IP扩展C段代码

Imports System.IO
Imports System.Text
Public Class Main
    Private AllIP As New List(Of String)
    Private AddAllIP As New List(Of String)
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        For Each temp1 As String In RichTextBox1.Lines
            AllIP.Add(temp1)
        Next
        Dim ResultBuilder As New StringBuilder  
        Dim Temp() As String
        For Each temp1 As String In AllIP
            If AddAllIP.Contains(temp1) = False Then
                Temp = temp1.Split(".")
                ResultBuilder.AppendFormat("{0}.{1}.{2}.1-255{3}", Temp(0), Temp(1), Temp(2), vbCrLf)
                AddAllIP.Add(temp1)
            End If
        Next
        RichTextBox2.AppendText(ResultBuilder.ToString)
        Dim WriteArrangeIP As New StreamWriter("DoneArrange.txt")
        WriteArrangeIP.Write(ResultBuilder.ToString)
        WriteArrangeIP.Close()
        WriteArrangeIP.Dispose()
        ResultBuilder = Nothing
        GC.Collect()
    End Sub
End Class