VB.NET中的List用法

Imports System.IOImports System.Data.OleDbPublic Class Form_mobilecodeFilter    Public list As New List(Of String)    Public mobilecode As New List(Of mobile)    Public loadlist As New List(Of plist)    '结构体    Public Structure mobile        Public mobilecode As String        Public Province As String        Public City As String        Public Card As String    End Structure    Public Structure plist        Public province As String        Public mobileNew As List(Of citylist)    End Structure    Public Structure citylist        Public city As String        Public mobilecontext As List(Of mobileLoadwritetxt)    End Structure    Public Structure mobileLoadwritetxt        Public context As String        Public mobilecode As String        Public Province As String        Public City As String        Public Card As String    End Structure    Private Sub Button_Importmobilecode_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Importmobilecode.Click        Dim fileName As String        OpenFileDialog_ImportMobileCode.Filter = "文本文件(*.txt)|*.txt"        OpenFileDialog_ImportMobileCode.ShowDialog()        fileName = OpenFileDialog_ImportMobileCode.FileName        TextBox_Importfilepath.Text = fileName        Dim path As String        Dim line As String = String.Empty        path = TextBox_Importfilepath.Text        Try            FileOpen(1, path, OpenMode.Input)        Catch ex As Exception            FileClose(1)            FileOpen(1, path, OpenMode.Input)        End Try        line = ""        Do While Not EOF(1)            Input(1, line)            If line.Trim <> "" Then                list.Add(line)            End If        Loop        FileClose(1)    End Sub    Private Sub Button_Checkout_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Checkout.Click        Dim fileName As String        Dim result As DialogResult = FolderBrowserDialog_download.ShowDialog()        fileName = FolderBrowserDialog_download.SelectedPath        Dim i, j, k As Integer        Dim cl As citylist        Dim mo As mobileLoadwritetxt        For i = 0 To loadlist.Count - 1            Dim txtpath As String = fileName & "\" & loadlist.Item(i).province            System.IO.Directory.CreateDirectory(txtpath)            For j = 0 To loadlist.Item(i).mobileNew.Count - 1                cl = loadlist.Item(i).mobileNew.Item(j)                Dim writefile As New StreamWriter(txtpath & "\" & cl.city & ".txt")                For k = 0 To cl.mobilecontext.Count - 1                    mo = cl.mobilecontext.Item(k)                    Dim context As String = mo.context                    Dim province As String = mo.Province                    Dim City As String = mo.City                    Dim mobilecode As String = mo.mobilecode                    Dim Card As String = mo.Card                    Dim writecontext As String = ""                    If CheckBox_ID.Checked Then                        writecontext = writecontext & k 1 & "   "                    End If                    If CheckBox_mobilecode.Checked Then                        writecontext = writecontext & context & "     "                    End If                    If CheckBox_province.Checked Then                        writecontext = writecontext & province & "    "                    End If                    If CheckBox_city.Checked Then                        writecontext = writecontext & City & "    "                    End If                    If CheckBox_haoduan.Checked Then                        writecontext = writecontext & mobilecode & "    "                    End If                    If CheckBox_execute.Checked Then                        writecontext = writecontext & Card                    End If                    writefile.WriteLine(writecontext)                Next                writefile.Flush()                writefile.Close()            Next        Next        TextBox_Importfilepath.Text = ""        MessageBox.Show("完成")    End Sub    Private Sub Button_closeMe_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_closeMe.Click        Me.Close()    End Sub    Public Sub loadmobile()        Dim SQLGroupStr = "select * from mobile"        Dim CString As String = " Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\ctc-nft.mdb;Persist Security Info=True"        Dim con As New OleDbConnection(CString)        Dim com As New OleDbCommand()        com.Connection = con        con.Open()        com.CommandType = CommandType.Text        com.CommandText = SQLGroupStr        Dim rs As OleDbDataReader = com.ExecuteReader()        While (rs.Read)            Dim m As New mobile            m.mobilecode = rs.GetString(0)            m.Province = rs.GetString(1)            m.City = rs.GetString(2)            m.Card = rs.GetString(3)            mobilecode.Add(m)        End While        con.Close()    End Sub    Private Sub Button_manage_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_manage.Click        loadmobile()        MessageBox.Show("在处理中可能要等几分钟，请稍等.........", "提示")        Dim i, j As Integer        Dim a As Integer = 1        Dim m As mobile        For i = 0 To mobilecode.Count - 1            m = mobilecode.Item(i)            For j = 0 To list.Count - 1                If m.mobilecode.ToString.Equals(list.Item(j).ToString.Substring(0, 7)) Then                    If a = 1 Then                        a = a 1                        Dim pl As New plist                        pl.province = mobilecode.Item(i).Province                        Dim lm As New citylist                        lm.city = mobilecode.Item(i).City                        Dim mo As New mobileLoadwritetxt                        mo.Card = mobilecode.Item(i).Card                        mo.City = mobilecode.Item(i).City                        mo.context = list.Item(j)                        mo.mobilecode = mobilecode.Item(i).mobilecode                        mo.Province = mobilecode.Item(i).Province                        lm.mobilecontext = New List(Of mobileLoadwritetxt)                        lm.mobilecontext.Add(mo)                        pl.mobileNew = New List(Of citylist)                        pl.mobileNew.Add(lm)                        loadlist.Add(pl)                    Else                        Dim sp As String = isProvince(loadlist, mobilecode.Item(i).Province)                        Dim str() As String = sp.Split(" ")                        Dim flagprovince As String = str(0)                        Dim flag As Boolean                        If flagprovince.ToString.Equals("1") Then                            flag = True                        Else                            flag = False                        End If                        If flag = True Then                            Dim sc As String = iscity(loadlist, mobilecode.Item(i).City)                            Dim str1() As String = sc.Split(" ")                            Dim flagcity As Boolean                            If str1(0).ToString.Equals("1") Then                                flagcity = True                            Else                                flagcity = False                            End If                            If flagcity = True Then                                Dim mob As New mobileLoadwritetxt                                mob.Card = mobilecode.Item(i).Card                                mob.City = mobilecode.Item(i).City                                mob.context = list.Item(j)                                mob.mobilecode = mobilecode.Item(i).mobilecode                                mob.Province = mobilecode.Item(i).Province                                loadlist.Item(str(1)).mobileNew.Item(str1(1)).mobilecontext.Add(mob)                            Else                                Dim cl As New citylist                                cl.city = mobilecode.Item(i).City                                Dim mi As New mobileLoadwritetxt                                mi.Card = mobilecode.Item(i).Card                                mi.City = mobilecode.Item(i).City                                mi.context = list.Item(j)                                mi.mobilecode = mobilecode.Item(i).mobilecode                                mi.Province = mobilecode.Item(i).Province                                cl.mobilecontext = New List(Of mobileLoadwritetxt)                                cl.mobilecontext.Add(mi)                                loadlist.Item(str(1)).mobileNew.Add(cl)                            End If                        Else                            Dim pl As New plist                            pl.province = mobilecode.Item(i).Province                            Dim lm As New citylist                            lm.city = mobilecode.Item(i).City                            Dim mo As New mobileLoadwritetxt                            mo.Card = mobilecode.Item(i).Card                            mo.City = mobilecode.Item(i).City                            mo.context = list.Item(j)                            mo.mobilecode = mobilecode.Item(i).mobilecode                            mo.Province = mobilecode.Item(i).Province                            lm.mobilecontext = New List(Of mobileLoadwritetxt)                            lm.mobilecontext.Add(mo)                            pl.mobileNew = New List(Of citylist)                            pl.mobileNew.Add(lm)                            loadlist.Add(pl)                        End If                        End If                End If            Next        Next        MessageBox.Show("请立即导入，当关闭此窗口数据就会销毁", "提示")    End Sub    Public Function isProvince(ByVal list As List(Of plist), ByVal str As String)        Dim i As Integer        For i = 0 To list.Count - 1            If str.ToString.Equals(list.Item(i).province.ToString) Then                Return 1 & " " & i            End If        Next        Return 0 & " " & i - 1    End Function    Public Function iscity(ByVal list As List(Of plist), ByVal str As String)        Dim i, j As Integer        Dim pl As plist        pl.mobileNew = New List(Of citylist)        Dim cl As citylist        For i = 0 To list.Count - 1            pl.mobileNew = list.Item(i).mobileNew            For j = 0 To pl.mobileNew.Count - 1                cl = pl.mobileNew.Item(j)                If cl.city.ToString.Equals(str) Then                    Return 1 & " " & j                End If            Next        Next        Return 0 & " " & j - 1    End FunctionEnd Class     '此段代码现给有一定编程基础的朋友