Sql 如何将图像从Picturebox（VB6中的图像）转换为字符串（Base64）？

早上好

我有一个vb6中的程序，它有一个名为Image3的控件，现在要让这个控件有一个图像，我必须浏览一张图片，最好是.jpg文件，因为我现在将它保存在我的SQL中，我不需要这样做，因为在不久的将来，系统会变慢，因为很多图像肯定会被保存。对我来说，最好的方法是将其转换为字符串，反之亦然。老实说，我不想问这个问题，因为它是可搜索的，我看到适合它的代码是IO.MemoryStream。我的问题是我在参考资料中看不到它。现在我尝试下载一个新的，但VB6不接受它

有人能用这个点亮我吗？将图像转换为字符串的其他方法

我这样做的原因是我将在select命令中使用转换为字符串的图像，因为memorystream是图像的唯一性

一般来说，我不想再上传同一张图片了

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TYSM已经完成了这个问题，对于那个些想要和我在这里做的一样的人来说，这是完整的代码

Private Sub Image3_DblClick()

CommonDialog1.InitDir = App.Path
CommonDialog1.FileName = ""
CommonDialog1.Filter = "Image files|*.jpg;"
CommonDialog1.DialogTitle = "All Picture Files"
CommonDialog1.ShowOpen

If CommonDialog1.FileName <> "" Then

        Dim arrImageByte() As Byte
        Dim bytBuf() As Byte
        Dim fNum As Integer
        Dim rs As New ADODB.Recordset
        Dim strPhotoPath As String
        Dim FileInputData As String
        Dim s As String

        Image3.Picture = LoadPicture(CommonDialog1.FileName)
        strPhotoPath = CommonDialog1.FileName

        ReDim arrImageByte(FileLen(strPhotoPath))
        fNum = FreeFile()
        Open strPhotoPath For Binary As #fNum
        Get #fNum, , arrImageByte
        Close fNum

        Open CommonDialog1.FileName For Binary As #1
        FileInputData = String(LOF(1), 0)
        Get #1, 1, FileInputData
        Close #1

        bytBuf = FileInputData

        s = CryptoBase64.Encode(bytBuf)

        Text8.Text = s

        Close

End If



--------------------------Class Module------------------------------

Option Explicit
Private Const CLASS_EXCEPT_BASE As Long = &H8004E300

Public Enum CryptoBase64ExceptEnum
  cbxGetOSVersFailed = CLASS_EXCEPT_BASE
  cbxNotNT
  cbxWinXPOrLaterReqd
  cbxWinVistaOrLaterReqd
  cbxStringToBinaryFailed
  cbxBinaryToStringFailed
End Enum

Public Enum Base64FormatEnum
  bfmtCrLF = 0
  bfmtLfOnly
  bfmtNone
End Enum

Public Enum OSVersionEnum
  osvWinXP = 501
  osvWinVista = 600
End Enum

Private Const VER_PLATFORM_WIN32_NT As Long = 2

Private Type OSVERSIONINFO
  dwOSVersionInfoSize As Long
  dwMajorVersion As Long
    ' Operating System     Value
    ' Windows 3.1            3
    ' Windows 95             4
    ' Windows 98             4
    ' Windows Me             4
    ' Windows NT 3.51        3
    ' Windows NT 4.0         4
    ' Windows 2000           5
    ' Windows XP             5
    ' Windows .Net Server    5
    ' Windows 2003 Server    5
    ' Windows 2003 R2 Server 5
    ' Windows Vista          6
    ' Windows 2008 Server    6
  dwMinorVersion As Long
    ' Operating System     Value
    ' Windows 3.1            1
    ' Windows 95             0
    ' Windows 98             10
    ' Windows Me             90
    ' Windows NT 3.51        51
    ' Windows NT 4.0         0
    ' Windows 2000           0
    ' Windows XP             1
    ' Windows .Net Server    1
    ' Windows 2003 Server    2
    ' Windows 2003 R2 Server 2
    ' Windows Vista          0
    ' Windows 2008 Server    0
    dwBuildNumber As Long
    dwPlatformId As Long
    szCSDVersion As String * 128

  'Extended information (optional), i.e. OSVERSIONINFOEX:
  wServicePackMajor As Integer
  wServicePackMinor As Integer
  wSuiteMask As Integer
  wProductType As Byte
    ' Operating System     Value
    ' NT Workstation         1
    ' NT Domain Controller   2
    ' NT Server              3
  wReserved As Byte
End Type

Private Declare Function GetVersionEx Lib "kernel32" Alias "GetVersionExA" (lpVersionInformation As OSVERSIONINFO) As Long

Private Const CRYPT_STRING_BASE64 As Long = 1
Private Const CRYPT_STRING_NOCR As Long = &H80000000
Private Const CRYPT_STRING_NOCRLF As Long = &H40000000

Private Declare Function CryptBinaryToString Lib "Crypt32" Alias "CryptBinaryToStringW" _
 (ByRef pbBinary As Byte, _
  ByVal cbBinary As Long, _
  ByVal dwFlags As Long, _
  ByVal pszString As Long, _
  ByRef pcchString As Long) As Long

Private Declare Function CryptStringToBinary Lib "Crypt32" Alias "CryptStringToBinaryW" _
 (ByVal pszString As Long, _
  ByVal cchString As Long, _
  ByVal dwFlags As Long, _
  ByVal pbBinary As Long, _
  ByRef pcbBinary As Long, _
  ByRef pdwSkip As Long, _
  ByRef pdwFlags As Long) As Long

Private m_OSVersion As OSVersionEnum
Private m_lngBase64Format As Long
Public Property Get Base64Format() As Base64FormatEnum
 If m_lngBase64Format = 0 Then
   Base64Format = bfmtCrLF
 ElseIf m_lngBase64Format = CRYPT_STRING_NOCR Then
   Base64Format = bfmtLfOnly
 Else
   Base64Format = bfmtNone
 End If
End Property
Public Property Let Base64Format(ByVal Format As Base64FormatEnum)
 If Format = bfmtLfOnly Then
   If m_OSVersion < osvWinXP Then
     Err.Raise cbxWinXPOrLaterReqd, "CryptoBase64.Base64Format", "This format is only supported in Windows XP/2003 and later"
   Else
     m_lngBase64Format = CRYPT_STRING_NOCR
   End If
 ElseIf Format = bfmtNone Then
   If m_OSVersion < osvWinVista Then
     Err.Raise cbxWinVistaOrLaterReqd, "CryptoBase64.Base64Format", "This format is only supported in Windows Vista/2008 and later"
   Else
     m_lngBase64Format = CRYPT_STRING_NOCRLF
   End If
 Else
   m_lngBase64Format = 0
 End If
End Property
Public Function Decode(ByRef Base64Buf As String) As Byte()
 Dim lngOutLen As Long
 Dim dwActualUsed As Long
 Dim bytBuf() As Byte

 ' Determine output buffer length required. Note:
 ' StrPtr(vbNullString) is just a way to get a null pointer,
 ' even though we're really talking about a Byte array here.
 CryptStringToBinary StrPtr(Base64Buf), _
                     Len(Base64Buf), _
                     CRYPT_STRING_BASE64, _
                     StrPtr(vbNullString), _
                     lngOutLen, _
                     0&, _
                     dwActualUsed

 ' Convert Base64 to binary.
 ReDim bytBuf(lngOutLen - 1)

 If CryptStringToBinary(StrPtr(Base64Buf), _
                        Len(Base64Buf), _
                        CRYPT_STRING_BASE64, _
                        VarPtr(bytBuf(0)), _
                        lngOutLen, _
                        0&, _
                        dwActualUsed) = 0 Then
   Err.Raise cbxStringToBinaryFailed, "CryptoBase64.Decode", "CryptStringToBinary failed, error " & CStr(Err.LastDllError)
 Else
   Decode = bytBuf
 End If

 'Open App.Path & "\MyTestGif.gif" For Binary As #1
 'Put #1, 1, Decode
 'Close #1


End Function
Public Function Encode(ByRef BinaryBuf() As Byte) As String
 Dim bytBuf() As Byte
 Dim lngOutLen As Long
 Dim strBase64 As String

 'Determine Base64 output String length required.
 CryptBinaryToString BinaryBuf(0), _
                     UBound(BinaryBuf) + 1, _
                     CRYPT_STRING_BASE64 Or m_lngBase64Format, _
                     StrPtr(vbNullString), _
                     lngOutLen

 'Convert binary to Base64.
 Encode = String(lngOutLen, 0)

 If CryptBinaryToString(BinaryBuf(0), _
                        UBound(BinaryBuf) + 1, _
                        CRYPT_STRING_BASE64 Or m_lngBase64Format, _
                        StrPtr(Encode), _
                        lngOutLen) = 0 Then

   Err.Raise cbxBinaryToStringFailed, "CryptoBase64.Encode", "CryptBinaryToString failed, error " & CStr(Err.LastDllError)
    End If
End Function
Public Property Get OSVersion() As OSVersionEnum
 OSVersion = m_OSVersion
End Property
Private Sub Class_Initialize()
 Dim osvinfData As OSVERSIONINFO

 With osvinfData
   .dwOSVersionInfoSize = Len(osvinfData)
   .szCSDVersion = ""

   If GetVersionEx(osvinfData) = 0 Then
     Err.Raise cbxGetOSVersFailed, "CryptoBase64 Initialize", "GetVersionEx failed, error " & CStr(Err.LastDllError)
   End If

   If .dwPlatformId <> VER_PLATFORM_WIN32_NT Then
     Err.Raise cbxNotNT, "CryptoBase64 Initialize", "CryptoAPI is only available on NT-based OSs"
   End If

   m_OSVersion = .dwMajorVersion * 100 + .dwMinorVersion
 End With

 Base64Format = bfmtCrLF
End Sub

---

只需添加picbox、按钮和一个模块，即可使其工作

首先，如果您的代码是VB6，那么为什么要添加VB.NET标记？你是故意误导我们还是不在乎浪费我们的时间？第二，为什么您认为在数据库中保存图像会很慢，而保存这些图像的文本表示却奇迹般地不慢呢？只需在web上搜索如何将图像保存到VB6中的数据库中，您将不会得到任何VB.NET结果，这样您就不会将您或我们的时间浪费在不相关的事情上。很抱歉，我将删除标记VB.NET我不需要按字面意思保存图像，我只想保存它的字符串并将其重新转换为图像，为什么您认为这会有好处？数据库中不会有真实的图片。它将是以任何一种方式存储的二进制数据。这些数据既可以表示图像，也可以表示以某种方式从图像生成的文本。文本的二进制表示形式不会比图像的二进制表示形式小，也可能比图像的二进制表示形式大，那么您实际得到了什么？好的，先生，您的权利，您能帮助我如何实现这一点吗？