vb.net 对于文件的的简单操作

    ''' <summary>
    ''' パラメータの読み書き
    ''' </summary>
    ''' <returns>成功か？失敗か？</returns>
    ''' <remarks></remarks>
    Public Function SaveOrReadParameters(ByVal writeOaread As String) As Boolean
        SaveOrReadParameters = False
        Dim temp As StreamWriter
        '目録を創建する
        If (Not Directory.Exists(FILEPATH)) Then
            Directory.CreateDirectory(FILEPATH)
        End If
        'ファイルを書く
        If writeOaread = "write" Then
            'ファイル判断存在か？
            Dim Boo_DirExist As Boolean = System.IO.File.Exists(filepath & fileName)
            If Boo_DirExist Then
                'ファイル存在
                File.Delete(FILEPATH & FILENAME)
                temp = File.CreateText(FILEPATH & FILENAME)
            Else
                'ファイルが無し
                temp = File.CreateText(FILEPATH & FILENAME)
            End If
            Try
                Using sw As StreamWriter = temp
                    sw.WriteLine(txtSyohin_kana.Text & ";")
                    sw.WriteLine(txtSyohin.Text & ";")
                    sw.WriteLine(txtBunnrui.Text & ";")
                    sw.WriteLine(txtNomekuti.Text & ";")
                    sw.WriteLine(txtMennkaa.Text & ";")
                    sw.WriteLine(txtYouki.Text & ";")
                    sw.WriteLine(txtYouryoumin.Text & ";")
                    sw.WriteLine(txtYouryoumax.Text & ";")
                    sw.WriteLine(txtTannkamin.Text & ";")
                    sw.WriteLine(txtTannkamax.Text)
                    sw.Flush()
                    sw.Close()
                End Using
            Catch ex As Exception
                Application.ExitThread()
            Finally

            End Try
            'ファイルを読む
        ElseIf writeOaread = "read" Then
            Dim line As String = String.Empty
            Dim Boo_DirExist As Boolean = System.IO.File.Exists(FILEPATH & FILENAME)
            If Boo_DirExist = False Then
                'ファイルが無し
                Return False
            End If
            Using sr As StreamReader = New StreamReader(FILEPATH & FILENAME)
                Do While sr.Peek() > 0
                    line = line & sr.ReadLine()
                Loop
                sr.Close()
            End Using
            If line <> "" Then
                txtSyohin_kana.Text = line.Split(";")(0)
                txtSyohin.Text = line.Split(";")(1)
                txtBunnrui.Text = line.Split(";")(2)
                txtNomekuti.Text = line.Split(";")(3)
                txtMennkaa.Text = line.Split(";")(4)
                txtYouki.Text = line.Split(";")(5)
                txtYouryoumin.Text = line.Split(";")(6)
                txtYouryoumax.Text = line.Split(";")(7)
                txtTannkamin.Text = line.Split(";")(8)
                txtTannkamax.Text = line.Split(";")(9)
            Else
                Return False
            End If
        End If
        Return True
    End Function