[转载代码]VB.NET 中查询 Linq to SQL 执行时的SQL语句

Imports System.Diagnostics
Imports System.Globalization
Imports System.IO
Imports System.Text''' <summary>
''' Implements a <see cref="TextWriter"/> for writing information to the debugger log.
''' </summary>
''' <seealso cref="Debugger.Log"/>
Public Class DebuggerWriter
Inherits TextWriter
Private _isOpen As Boolean
Private Shared _encoding As UnicodeEncoding
Private ReadOnly _level As Integer
Private ReadOnly _category As String ''' <summary>
''' Initializes a new instance of the <see cref="DebuggerWriter"/> class.
''' </summary>
Public Sub New()
Me.New(, Debugger.DefaultCategory)
End Sub ''' <summary>
''' Initializes a new instance of the <see cref="DebuggerWriter"/> class with the specified level and category.
''' </summary>
''' <param name="level">A description of the importance of the messages.</param>
''' <param name="category">The category of the messages.</param>
Public Sub New(ByVal level As Integer, ByVal category As String)
Me.New(level, category, CultureInfo.CurrentCulture)
End Sub ''' <summary>
''' Initializes a new instance of the <see cref="DebuggerWriter"/> class with the specified level, category and format provider.
''' </summary>
''' <param name="level">A description of the importance of the messages.</param>
''' <param name="category">The category of the messages.</param>
''' <param name="formatProvider">An <see cref="IFormatProvider"/> object that controls formatting.</param>
Public Sub New(ByVal level As Integer, ByVal category As String, ByVal formatProvider As IFormatProvider)
MyBase.New(formatProvider)
Me._level = level
Me._category = category
Me._isOpen = True
End Sub Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
_isOpen = False
MyBase.Dispose(disposing)
End Sub Public Overloads Overrides Sub Write(ByVal value As Char)
If Not _isOpen Then
Throw New ObjectDisposedException(Nothing)
End If
Debugger.Log(level, category, value.ToString())
End Sub Public Overloads Overrides Sub Write(ByVal value As String)
If Not _isOpen Then
Throw New ObjectDisposedException(Nothing)
End If
If value <> Nothing Then
Debugger.Log(level, category, value)
End If
End Sub Public Overloads Overrides Sub Write(ByVal buffer As Char(), ByVal index As Integer, ByVal count As Integer)
If Not _isOpen Then
Throw New ObjectDisposedException(Nothing)
End If
If buffer = Nothing OrElse index < OrElse count < OrElse buffer.Length - index < count Then
' delegate throw exception to base class
MyBase.Write(buffer, index, count)
End If
Debugger.Log(level, category, New String(buffer, index, count))
End Sub Public Overloads Overrides ReadOnly Property Encoding() As Encoding
Get
If _encoding Is Nothing Then
_encoding = New UnicodeEncoding(False, False)
End If
Return _encoding
End Get
End Property Public ReadOnly Property Level() As Integer
Get
Return Level
End Get
End Property Public ReadOnly Property Category() As String
Get
Return _category
End Get
End Property
End Class

Dim tran As New Transactions.TransactionScope
Using tran
db.Log = New DebuggerWriter
db.SubmitChanges()
tran.Dispose()
End Using