VB.NET 创建文件以及文件的读写

Dim strFile As String = String.Format("C:\ErrorLog.txt", DateTime.Today.ToString("dd-MMM-yyyy"))
File.AppendAllText(strFile, String.Format("Error Message in  Occured at-- {0}{1}", DateTime.Now, Environment.NewLine))

                           ‘读取数据库中bin文件
                            Dim blobFiles As Integer = 0
                            Try
                                System.IO.Directory.CreateDirectory("C:\var\")
                                myCommand.CommandText = "select  blobFile from  evnet.join_server_firmware_version order by dttDateTime desc" ‘从数据库中读取存放文件字段按时间最新
                                Dim dr As MySqlDataReader = myCommand.ExecuteReader()
                                dr.Read()
                                Dim b(dr.GetBytes(blobFiles, 0, Nothing, 0, Integer.MaxValue) - 1) As Byte ‘声明b数组存放读取到的dr
                                dr.GetBytes(blobFiles, 0, b, 0, b.Length) ‘将b读取到的数存放在blobFiles中
                                dr.Close()
                                conn.Close()
                                conn.Open()
                                myCommand.CommandText = "select  vchfimware_versionName from  evnet.join_server_firmware_version order by dttDateTime desc"
                                VersionName = myCommand.ExecuteScalar
                                conn.Close()
                                If System.IO.File.Exists("C:\var\" + VersionName + ".txt") Then ‘判断当前c盘是否存储有该文件夹

                                Else
                                    Dim fs12 As New System.IO.FileStream("C:\var\" + VersionName + ".txt ", FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite)  ‘无则创建改文件
                                    fs12.Write(b, blobFiles, b.Length) ‘向创建的文件中开始写，一次性写完
                                    fs12.Close() ‘关闭读写操作，以免引发异常
                                    fs12.Dispose()
                                End If
                                ‘======================
                            Catch ex As Exception
                                Debug.Print("#######################" & ex.StackTrace)
                                Debug.Print("########" & ex.Message)
                                Throw ex
                            End Try

 Dim fs As New System.IO.FileStream("C:\var\" + VersionName + ".txt", IO.FileMode.Open, IO.FileAccess.Read)  Dim buffer(1023) As Byte
 Dim re As New System.IO.BinaryReader(fs)
 Dim numdouble As Double = (fs.Length / 1024)
 num = Math.Ceiling(numdouble) ‘此函数用于判断是否有小数，有小数将自动取整比如：1.2将会取2，1.6将会取2
 fs.Seek(i * ByNum.c, SeekOrigin.Begin)
 re.Read(buffer, 0, 1024) ‘表示从0位开始读1024位 如果想取分组包长度可用 buffer.Length  如果想取数据则直接可取buffer