如果您只需要服务器上所有文件夹和子文件夹的集合，您可以分页请求并仅通过几个调用从服务器获取整个文件夹层次结构。关键是
FolderView.Traversal属性。
例如，对于具有约1,300个文件夹的Exchange邮箱，下面的代码仅进行了2个请求。您可以将页面大小设置为任何您喜欢的大小，只要保持在或低于服务器限制即可。
FYI：Exchange Online（Office365）最多可以响应1,000个项目。我没有测试过，在查询本地Exchange Server时是否存在类似的限制。
Imports Exchange = Microsoft.Exchange.WebServices.Data
Friend Module Main
Public Sub Main()
Dim oService As Exchange.ExchangeService
Dim oUsers As Dictionary(Of String, User)
oUsers = New Dictionary(Of String, User)
oUsers.Add("User1", New User("write.to.me1@my.address.com", "Some-Fancy-Password1"))
oUsers.Add("User2", New User("write.to.me2@my.address.com", "Some-Fancy-Password2"))
oUsers.ToList.ForEach(Sub(Credential As KeyValuePair(Of String, User))
File.Delete(LOG_FILE_PATH.ToFormat(Credential.Key))
End Sub)
oUsers.ToList.ForEach(Sub(Credential As KeyValuePair(Of String, User))
LogFileName = Credential.Key
Console.WriteLine("Getting message counts for mailbox [{0}]...", LogFileName)
Console.WriteLine()
oService = Service.ConnectToService(Credential.Value)
GetAllFolders(oService, LOG_FILE_PATH.ToFormat(Credential.Key))
Console.Clear()
End Sub)
Console.WriteLine()
Console.Write("Press any key to exit...")
Console.ReadKey()
End Sub
Private Sub GetAllFolders(Service As Exchange.ExchangeService, LogFilePath As String)
Dim oIsHidden As Exchange.ExtendedPropertyDefinition
Dim oFolders As List(Of Exchange.Folder)
Dim oResults As Exchange.FindFoldersResults
Dim lHasMore As Boolean
Dim oChild As Exchange.Folder
Dim oView As Exchange.FolderView
Dim _
nPageSize,
nOffSet As Short
Dim _
oPaths,
oPath As List(Of String)
oIsHidden = New Exchange.ExtendedPropertyDefinition(&H10F4, Exchange.MapiPropertyType.Boolean)
nPageSize = 1000
oFolders = New List(Of Exchange.Folder)
lHasMore = True
nOffSet = 0
Do While lHasMore
oView = New Exchange.FolderView(nPageSize, nOffSet, Exchange.OffsetBasePoint.Beginning)
oView.PropertySet = New Exchange.PropertySet(Exchange.BasePropertySet.IdOnly)
oView.PropertySet.Add(oIsHidden)
oView.PropertySet.Add(Exchange.FolderSchema.ParentFolderId)
oView.PropertySet.Add(Exchange.FolderSchema.DisplayName)
oView.PropertySet.Add(Exchange.FolderSchema.FolderClass)
oView.PropertySet.Add(Exchange.FolderSchema.TotalCount)
oView.Traversal = Exchange.FolderTraversal.Deep
oResults = Service.FindFolders(Exchange.WellKnownFolderName.MsgFolderRoot, oView)
oFolders.AddRange(oResults.Folders)
lHasMore = oResults.MoreAvailable
If lHasMore Then
nOffSet += nPageSize
End If
Loop
oFolders.RemoveAll(Function(Folder) Folder.ExtendedProperties(0).Value = True)
oFolders.RemoveAll(Function(Folder) Folder.FolderClass <> "IPF.Note")
oPaths = New List(Of String)
oFolders.ForEach(Sub(Folder)
oChild = Folder
oPath = New List(Of String)
Do
oPath.Add(oChild.DisplayName)
oChild = oFolders.SingleOrDefault(Function(Parent) Parent.Id.UniqueId = oChild.ParentFolderId.UniqueId)
Loop While oChild IsNot Nothing
oPath.Reverse()
oPaths.Add("{0}{1}{2}".ToFormat(Join(oPath.ToArray, DELIMITER), vbTab, Folder.TotalCount))
End Sub)
oPaths.RemoveAll(Function(Path) Path.StartsWith("Sync Issues"))
File.WriteAllText(LogFilePath, Join(oPaths.ToArray, vbCrLf))
End Sub
Private LogFileName As String
Private Const LOG_FILE_PATH As String = "D:\Emails\Remote{0}.txt"
Private Const DELIMITER As String = "\"
End Module
Friend Class Service
Public Shared Function ConnectToService(User As User) As Exchange.ExchangeService
Return Service.ConnectToService(User, Nothing)
End Function
Public Shared Function ConnectToService(User As User, Listener As Exchange.ITraceListener) As Exchange.ExchangeService
Dim oService As Exchange.ExchangeService
oService = New Exchange.ExchangeService(Exchange.ExchangeVersion.Exchange2013_SP1)
oService.Credentials = New NetworkCredential(User.EmailAddress, User.Password)
oService.AutodiscoverUrl(User.EmailAddress, AddressOf RedirectionUrlValidationCallback)
If Listener IsNot Nothing Then
oService.TraceListener = Listener
oService.TraceEnabled = True
oService.TraceFlags = Exchange.TraceFlags.All
End If
Return oService
End Function
Private Shared Function RedirectionUrlValidationCallback(RedirectionUrl As String) As Boolean
With New Uri(RedirectionUrl)
Return .Scheme.ToLower = "https"
End With
End Function
End Class
Friend Class User
Public Sub New(EmailAddress As String)
_EmailAddress = EmailAddress
_Password = New SecureString
End Sub
Public Sub New(EmailAddress As String, Password As String)
_EmailAddress = EmailAddress
_Password = New SecureString
Password.ToList.ForEach(Sub(Chr As Char)
Me.Password.AppendChar(Chr)
End Sub)
Password.MakeReadOnly()
End Sub
Public Shared Function GetUser() As User
Dim sEmailAddress As String
Dim oUserInput As ConsoleKeyInfo
Console.Write("Enter email address: ")
sEmailAddress = Console.ReadLine
Console.Write("Enter password: ")
GetUser = New User(sEmailAddress)
While True
oUserInput = Console.ReadKey(True)
If oUserInput.Key = ConsoleKey.Enter Then
Exit While
ElseIf oUserInput.Key = ConsoleKey.Escape Then
GetUser.Password.Clear()
ElseIf oUserInput.Key = ConsoleKey.Backspace Then
If GetUser.Password.Length <> 0 Then
GetUser.Password.RemoveAt(GetUser.Password.Length - 1)
End If
Else
GetUser.Password.AppendChar(oUserInput.KeyChar)
Console.Write("*")
End If
End While
If GetUser.Password.Length = 0 Then
GetUser = Nothing
Else
GetUser.Password.MakeReadOnly()
Console.WriteLine()
End If
End Function
Public ReadOnly Property EmailAddress As String
Public ReadOnly Property Password As SecureString
End Class
Friend Class TraceListener
Implements Exchange.ITraceListener
Public Sub Trace(TraceType As String, TraceMessage As String) Implements Exchange.ITraceListener.Trace
File.AppendAllText("{0}.txt".ToFormat(Path.Combine("D:\Emails\TraceOutput", Guid.NewGuid.ToString("D"))), TraceMessage)
End Sub
End Class
