枚举计算机上设置的DSN列表

Question

我有一个Excel应用程序,我想在其中向用户显示数据源名称列表(即:DSN),从而他/她可以选择使用哪个数据源.

希望一旦我有了列表,我就可以轻松访问DSN属性以连接到相应的数据库.

请注意,我不希望使用一个DSN-less连接.

Answer 1

DSN条目存储在注册表中的以下键中.

HKEY_CURRENT_USER\Software\ODBC\ODBC.INI\ODBC Data Sources
HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI\ODBC Data Sources

它包含所有已定义DSN的列表.这充当全局索引,每个DSN的特定详细信息存储在DSN名称下的密钥中:

HKEY_CURRENT_USER\Software\ODBC\ODBC.INI
HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI

在"数据源(ODBC)"控制面板小程序的"用户DSN"和"系统DSN"选项卡中创建一些条目,并检查这些值在注册表中的存储方式.

以下示例通过控制面板>管理工具>数据源(ODBC)[用户Dsn选项卡]枚举为用户定义的DSN.

http://support.microsoft.com/kb/178755

  Option Explicit

  Private Declare Function RegOpenKeyEx Lib "advapi32.dll" _
      Alias "RegOpenKeyExA" _
      (ByVal hKey As Long, _
      ByVal lpSubKey As String, _
      ByVal ulOptions As Long, _
      ByVal samDesired As Long, phkResult As Long) As Long

  Private Declare Function RegEnumValue Lib "advapi32.dll" _
      Alias "RegEnumValueA" _
      (ByVal hKey As Long, _
      ByVal dwIndex As Long, _
      ByVal lpValueName As String, _
      lpcbValueName As Long, _
      ByVal lpReserved As Long, _
      lpType As Long, _
      lpData As Any, _
      lpcbData As Long) As Long

  Private Declare Function RegCloseKey Lib "advapi32.dll" _
      (ByVal hKey As Long) As Long

  Const HKEY_CLASSES_ROOT = &H80000000
  Const HKEY_CURRENT_USER = &H80000001
  Const HKEY_LOCAL_MACHINE = &H80000002
  Const HKEY_USERS = &H80000003

  Const ERROR_SUCCESS = 0&

  Const SYNCHRONIZE = &H100000
  Const STANDARD_RIGHTS_READ = &H20000
  Const STANDARD_RIGHTS_WRITE = &H20000
  Const STANDARD_RIGHTS_EXECUTE = &H20000
  Const STANDARD_RIGHTS_REQUIRED = &HF0000
  Const STANDARD_RIGHTS_ALL = &H1F0000
  Const KEY_QUERY_VALUE = &H1
  Const KEY_SET_VALUE = &H2
  Const KEY_CREATE_SUB_KEY = &H4
  Const KEY_ENUMERATE_SUB_KEYS = &H8
  Const KEY_NOTIFY = &H10
  Const KEY_CREATE_LINK = &H20
  Const KEY_READ = ((STANDARD_RIGHTS_READ Or _
                    KEY_QUERY_VALUE Or _
                    KEY_ENUMERATE_SUB_KEYS Or _
                    KEY_NOTIFY) And _
                    (Not SYNCHRONIZE))

  Const REG_DWORD = 4
  Const REG_BINARY = 3
  Const REG_SZ = 1

  Private Sub Command1_Click()
     Dim lngKeyHandle As Long
     Dim lngResult As Long
     Dim lngCurIdx As Long
     Dim strValue As String
     Dim lngValueLen As Long
     Dim lngData As Long
     Dim lngDataLen As Long
     Dim strResult As String

     lngResult = RegOpenKeyEx(HKEY_CURRENT_USER, _
             "SOFTWARE\ODBC\ODBC.INI\ODBC Data Sources", _
              0&, _
              KEY_READ, _
              lngKeyHandle)

     If lngResult <> ERROR_SUCCESS Then
         MsgBox "Cannot open key"
         Exit Sub
     End If

     lngCurIdx = 0
     Do
        lngValueLen = 2000
        strValue = String(lngValueLen, 0)
        lngDataLen = 2000

        lngResult = RegEnumValue(lngKeyHandle, _
                                 lngCurIdx, _
                                 ByVal strValue, _
                                 lngValueLen, _
                                 0&, _
                                 REG_DWORD, _
                                 ByVal lngData, _
                                 lngDataLen)
        lngCurIdx = lngCurIdx + 1

        If lngResult = ERROR_SUCCESS Then
           strResult = strResult & lngCurIdx & ": " & Left(strValue, lngValueLen) & vbCrLf
        End If
     Loop While lngResult = ERROR_SUCCESS
     Call RegCloseKey(lngKeyHandle)

     Call MsgBox(strResult, vbInformation)
  End Sub