把这个班

Imports System.Runtime.InteropServices
Imports System.Text

Public Class SQLInfoEnumerator

    <DllImport("odbc32.dll")>
    Private Shared Function SQLAllocHandle(handleType As Short, inputHandle As IntPtr, ByRef outputHandlePtr As IntPtr) As Short
    End Function
    <DllImport("odbc32.dll")>
    Private Shared Function SQLSetEnvAttr(environmentHandle As IntPtr, attribute As Integer, valuePtr As IntPtr, stringLength As Integer) As Short
    End Function
    <DllImport("odbc32.dll")>
    Private Shared Function SQLFreeHandle(hType As Short, Handle As IntPtr) As Short
    End Function
    <DllImport("odbc32.dll", CharSet:=CharSet.Ansi)>
    Private Shared Function SQLBrowseConnect(handleConnection As IntPtr, inConnection As StringBuilder, stringLength As Short, outConnection As StringBuilder, bufferLength As Short, ByRef stringLength2Ptr As Short) As Short
    End Function

    Private Const SQL_DRIVER_STR As String = "DRIVER=SQL SERVER"
    Private Const SQL_SUCCESS As Short = 0
    Private Const SQL_HANDLE_ENV As Short = 1
    Private Const SQL_HANDLE_DBC As Short = 2
    Private Const SQL_ATTR_ODBC_VERSION As Integer = 200
    Private Const SQL_OV_ODBC3 As Integer = 3
    Private Const SQL_NEED_DATA As Short = 99
    Private Const DEFAULT_RESULT_SIZE As Short = 1024
    Private Const START_STR As String = "{"
    Private Const END_STR As String = "}"

    ''' <summary>
    ''' A string to hold the selected SQL Server
    ''' </summary>
    Private m_SQLServer As String
    ''' <summary>
    ''' A string to hold the username
    ''' </summary>
    Private m_Username As String
    ''' <summary>
    ''' A string to hold the password
    ''' </summary>
    Private m_Password As String
    ''' <summary>
    ''' Property to set the SQL Server instance
    ''' </summary>
    Public WriteOnly Property SQLServer() As String
        Set(value As String)
            m_SQLServer = value
        End Set
    End Property
    ''' <summary>
    ''' Property to set the Username
    ''' </summary>
    Public WriteOnly Property Username() As String
        Set(value As String)
            m_Username = value
        End Set
    End Property
    ''' <summary>
    ''' Property to set the Password
    ''' </summary>
    Public WriteOnly Property Password() As String
        Set(value As String)
            m_Password = value
        End Set
    End Property

    ''' <summary>
    ''' Enumerate the SQL Servers returning a list (if any exist)
    ''' </summary>
    ''' <returns></returns>
    Public Function EnumerateSQLServers() As String()
        Return RetrieveInformation(SQL_DRIVER_STR)
    End Function
    ''' <summary>
    ''' Enumerate the specified SQL server returning a list of databases (if any exist)
    ''' </summary>
    ''' <returns></returns>
    Public Function EnumerateSQLServersDatabases() As String()
        Return RetrieveInformation(Convert.ToString((Convert.ToString((Convert.ToString(SQL_DRIVER_STR & Convert.ToString(";SERVER=")) & m_SQLServer) + ";UID=") & m_Username) + ";PWD=") & m_Password)
    End Function

    ''' <summary>
    ''' Enumerate for SQLServer/Databases based on the passed information it the string
    ''' The more information provided to SQLBrowseConnect the more granular it gets so
    ''' if only DRIVER=SQL SERVER passed then a list of all SQL Servers is returned
    ''' If DRIVER=SQL SERVER;Server=ServerName is passed then a list of all Databases on the
    ''' servers is returned etc
    ''' </summary>
    ''' <param name="InputParam">A valid string to query for</param>
    ''' <returns></returns>
    Private Function RetrieveInformation(InputParam As String) As String()
        Dim m_environmentHandle As IntPtr = IntPtr.Zero
        Dim m_connectionHandle As IntPtr = IntPtr.Zero
        Dim inConnection As New StringBuilder(InputParam)
        Dim stringLength As Short = CShort(inConnection.Length)
        Dim outConnection As New StringBuilder(DEFAULT_RESULT_SIZE)
        Dim stringLength2Ptr As Short = 0
        Try
            If SQL_SUCCESS = SQLAllocHandle(SQL_HANDLE_ENV, m_environmentHandle, m_environmentHandle) Then
                If SQL_SUCCESS = SQLSetEnvAttr(m_environmentHandle, SQL_ATTR_ODBC_VERSION, New IntPtr(SQL_OV_ODBC3), 0) Then
                    If SQL_SUCCESS = SQLAllocHandle(SQL_HANDLE_DBC, m_environmentHandle, m_connectionHandle) Then
                        If SQL_NEED_DATA = SQLBrowseConnect(m_connectionHandle, inConnection, stringLength, outConnection, DEFAULT_RESULT_SIZE, stringLength2Ptr) Then
                            If SQL_NEED_DATA <> SQLBrowseConnect(m_connectionHandle, inConnection, stringLength, outConnection, DEFAULT_RESULT_SIZE, stringLength2Ptr) Then
                                Throw New ApplicationException("No Data Returned.")
                            End If
                        End If
                    End If
                End If
            End If

        Catch ex As Exception
            Throw New ApplicationException("Cannot Locate SQL Server.")
        Finally
            FreeConnection(m_connectionHandle)
            FreeConnection(m_environmentHandle)
        End Try
        If outConnection.ToString() <> "" Then
            Return ParseSQLOutConnection(outConnection.ToString())
        Else
            Return Nothing
        End If

    End Function
    ''' <summary>
    ''' Parse an outConnection string returned from SQLBrowseConnect
    ''' </summary>
    ''' <param name="outConnection">string to parse</param>
    ''' <returns></returns>
    Private Function ParseSQLOutConnection(outConnection As String) As String()
        Dim m_Start As Integer = outConnection.IndexOf(START_STR) + 1
        Dim m_lenString As Integer = outConnection.IndexOf(END_STR) - m_Start
        If (m_Start > 0) AndAlso (m_lenString > 0) Then
            outConnection = outConnection.Substring(m_Start, m_lenString)
        Else
            outConnection = String.Empty
        End If
        Return outConnection.Split(",".ToCharArray())
    End Function
    Private Sub FreeConnection(handleToFree As IntPtr)
        If handleToFree <> IntPtr.Zero Then
            SQLFreeHandle(SQL_HANDLE_DBC, handleToFree)
        End If
    End Sub

End Class

并添加此方法

Private Sub GetSQLDetails(SQLListBox As ListBox)
    Dim sie As New SQLInfoEnumerator()
    Try
        If SQLListBox.Name = "listboxSQLServerDatabaseInstances" Then
            SQLListBox.Items.Clear()
            sie.SQLServer = listboxSQLServerInstances.SelectedItem.ToString()
            sie.Username = textboxUserName.Text
            sie.Password = textboxPassword.Text
            SQLListBox.Items.AddRange(sie.EnumerateSQLServersDatabases())
        Else
            SQLListBox.Items.Clear()
            SQLListBox.Items.AddRange(sie.EnumerateSQLServers())
        End If
    Catch ex As Exception
        MessageBox.Show(ex.ToString())
    End Try
End Sub