簡易執行方式
1. 確定Program.cs有加上Su.Encryption.AesEncryptor.InitAesPaddingEncryptor(secret , iv , encKey , dataRoot)
2. 確定appsettings.json有設定變數，DataRoot、EnvironmentEncKey
3. 先執行一次，會報錯誤，在dataRoot位置會產生一組$"{encKey}.ps1，裡面會放設定環境變數的指令
4. 設定完，記得把 $"{encKey}.ps1檔案刪除
===以上，設定完環境變數===
1. 確定Program.cs有加上Dictionary<string, string> encSetting = Su.Encryption.GetDecryptedSetting
2. 確定appsettings.json有設定變數，DataRoot、EnvironmentEncKey , ShowEncSetting 設定為 false
3. 在 $"{dataRoot}\Config\XXXX_dec.json"設定DBC連線，要注意連線字串要加上  "TrustServerCertificate=true;"，因為.net Core一定要藥用SSL連線
4. 設定完之後，在執行一次，會自動產生XXXX.json
5. 刪除XXXX_dec.json
===以上，產生完加密DBC連線
備註，要取回解密連線字串，appsettings.json有設定變數 , ShowEncSetting 設定為 true

概念解說
原本  >> config大多是明文，駭客可以藉由偷到config來知道變數設定，例如  dbc連線資訊、某個APP Key
之後  >> 將重要資訊分成兩段，
appsettings.json  >>  放可公開資訊的設定，例如 DataRoot、EnvironmentEncKey

在環境變數加上一個 由本機產生的隨機變數
讓本機的所有


原理說明
1. .Net Core 啟動時最先執行檔案 Program.cs，在一開頭先檢查本機是否有設定環境變數
緯中用的function Su.Encryption.AesEncryptor.InitAesPaddingEncryptor(secret , iv , encKey , dataRoot)
進階加密標準（英語：Advanced Encryption Standard，縮寫：AES）

沒有的話，會在 dataRoot 這邊產生一個 encKey.ps1的檔案，裡面放有環境變數設定的指令
(encSecretAndIv = Su.Encryption.AesEncryptor.Encrypt(envSecret, envIv, Su.TextFns.GetRandomString(48));
var command = $"[Environment]::SetEnvironmentVariable('{variableName}', '{encSecretAndIv}', 'Machine')";)
(隨機產生48碼亂數，(前32碼為本機專用Secret、後16碼為iv)，進行aes加密)




 

主要是使用 Printing.PreviewPrintController 的產生預覽圖片的功能來儲存列印內容, 再把圖片送到印表機, 以保証列印內容和儲存的圖檔是一致的. 值得一提的是, 在預覽時可以使用不同的印表機, 以便讓產生較小的圖檔, 否則有時會發生 GDI+ 的錯誤.

Sample 如下:

Imports System.Drawing.Printing

Namespace X

    Partial Public Class PrintSomething

        Dim PD As PrintDocument

        Dim ppc As New Printing.PreviewPrintController()

        Dim TotalPage As Int32 = 0

        ''' <summary>

        ''' 第幾次列印, 用來控制寫出的圖檔

        ''' </summary>

        ''' <remarks></remarks>

        Dim PrintCount As Int32 = 1

        Dim PageCount As Int32 = 1

            :

            :

            :

      

        Sub New(ByVal oPM As DB.PackingListMain, ByVal dtDetail As DataTable, dtUsedCoupon As DataTable)

            '初始化資料

            :

            :

            :

        End Sub

        Sub InitPrintDocument()

            '在這裡設定 PrintDocument 的紙張, 印表機, 邊界, 橫印或直印

            PD = New PrintDocument

            :

            :

            :

        End Sub

        Sub print()

            InitPrintDocument()

            PD.PrintController = ppc

           

            ' 第一次先把列印結果存在 Printing.PreviewPrintController 中

            AddHandler PD.PrintPage, AddressOf GeneratePreview

            '再來儲存圖片

            AddHandler PD.EndPrint, AddressOf SaveImage

            PD.Print()

        End Sub



        Dim ppi() As Printing.PreviewPageInfo

        Dim PrintPage As Int32 = 0

        Sub SaveImage(ByVal sender As Object, ByVal ev As PrintEventArgs)

            PrintDebug("Save Image Start, " & Now.ToString("yyyy-MM-dd HH:mm:ss.fff"))

            '把圖檔存起來

            Dim TF As String = Now.ToString("yyyyMMddHHmmss") ' DB.SysConfig.Path.LocalDataRoot

            Dim PathLocal As String = "C:\PrintLog\" & TF.Substring(0, 4) & "-" & TF.Substring(4, 2) & "\"

            Dim PathPackingListSheetImage As String = DB.SysConfig.PackingListSheetImage & TF.Substring(0, 4) & "-" & TF.Substring(4, 2) & "\"

            System.IO.Directory.CreateDirectory(PathLocal)

            System.IO.Directory.CreateDirectory(PathPackingListSheetImage)

            Dim LatestImages As String = ""

            ppi = ppc.GetPreviewPageInfo()

            For x As Integer = 0 To ppi.Length - 1

                Dim Filename As String = TF & "_" & Me.oPM.Id & "_" & x & ".png"

                ppi(x).Image.Save(PathLocal & Filename, System.Drawing.Imaging.ImageFormat.Png)

            Next



            '把圖檔印出來

            For x As Integer = 0 To ppi.Length - 1

  '建立新的 PrintDocument

                InitPrintDocument()

                If CST.WebConfig.Server_NAME = "測試主機" Then

                    UW.WU.DebugWriteLine("PrinterName: " & Me.PD.PrinterSettings.PrinterName)

                    UW.WU.DebugWriteLine("PaperSize: " & PD.DefaultPageSettings.PaperSize.PaperName)

                    PD.DocumentName = "PackingList"

                    PD.PrinterSettings.PrintFileName = "C:\PDF\PackingList" & Now.ToString("yyyyMMddHHmmss") & "_" & PrintPage & ".prn"

                    PD.PrinterSettings.PrintToFile = True

                    'PD.PrinterSettings.

                End If

                '很奇怪, 這裡不會分頁, 所以要一張一張印   

                AddHandler PD.PrintPage, AddressOf pd_PrintPage2

                PD.Print()



               PrintPage += 1

            Next

        End Sub

        Private Sub pd_PrintPage2(ByVal sender As Object, ByVal ev As PrintPageEventArgs)

            '很奇怪, 這裡不會分頁, 所以要一張一張印           

            ev.Graphics.DrawImage(ppi(PrintPage).Image, 0, 0)

            ev.HasMorePages = False

        End Sub



        Private Sub GeneratePreview(ByVal sender As Object, ByVal ev As PrintPageEventArgs)

            ' 列印內容

        End Sub

        End Class

    End Class

End Namespace