vba - 为在完成前进入无响应状态的宏提供状态更新

Question

我有一个 VBA 宏来搜索电子邮件文件。

当搜索数万封电子邮件时(在我的测试机器上甚至只有几百封)，它会显示几秒钟的状态，然后在搜索其余电子邮件时进入“无响应”状态。

这导致不耐烦的用户过早地结束了任务，我想通过提供状态更新来纠正这个问题。

我编写了以下解决方案，并认为问题出在循环期间 VBA 中 GarbageCollector 的运行方式上。

Public Sub searchAndMove()

    UserForm1.Show

    ' Send a message to the user indicating
    ' the program has completed successfully, 
    ' and displaying the number of messages sent during the run.

End Sub

Private Sub UserForm_Activate()

Me.Width = 240
Me.Height = 60

Me.Label1.Width = 230
Me.Label1.Height = 50

Dim oSelectTarget As Outlook.Folder
Dim oMoveTarget As Outlook.Folder
Dim oSearchCriteria As String

' Select the target folder to search and then the folder to
' which the files should be moved
Set oSelectTarget = Application.Session.PickFolder
Set oMoveTarget = Application.Session.PickFolder

oSearchCriteria = InputBox("Input search string: ")

Dim selectedItems As Outlook.Items
Set selectedItems = oSelectTarget.Items
Dim selectedEmail As Outlook.MailItem

Dim StatusBarMsg As String
StatusBarMsg = ""

Dim initialCount As Long
initialCount = selectedItems.count


Dim movedCounter As Long
movedCounter = 0
Dim x As Long
Dim exists As Long

' Function Loop, stepping backwards
' to prevent errors derived from modifying the collection
For x = selectedItems.count To 1 Step -1
    Set selectedEmail = selectedItems.Item(x)
    ' Test to determine if the subject contains the search string

    exists = InStr(selectedEmail.Subject, oSearchCriteria)
    If Len(selectedEmail.Subject) > 999 Then
        selectedEmail.Move oMoveTarget
    Else:
        If exists <> 0 Then
            selectedEmail.Move oMoveTarget
            movedCounter = (movedCounter + 1)
        Else: End If
    End If
    Set selectedEmail = Nothing
    StatusBarMsg = "Processing " & x & " out of " & initialCount & " messages."

    UserForm1.Label1.Caption = StatusBarMsg
    UserForm1.Repaint
Next x

Dim Msg As String
Dim Response
Msg = "SearchAndMove has detected and moved " & movedCounter & _
  " messages since last run."
Response = MsgBox(Msg, vbOKOnly)


' Close the References to prevent a reference leak
Set oSelectTarget = Nothing
Set oMoveTarget = Nothing
Set selectedItems = Nothing
Set selectedEmail = Nothing

Unload Me

End Sub

Answer 1

换行

UserForm1.Repaint

到

DoEvents

是的，这会增加执行时间，但如果有数千封电子邮件，那么您就别无选择。

提示: 你也可能想改变

StatusBarMsg = "Processing "& x & "out of "& initialCount & "条消息。"

到

StatusBarMsg = "请不要打断。正在处理 "& x & "out of "& initialCount & "消息。"

此外，建议您在流程开始时告知您的用户这可能需要一些时间，因此他们可以在确定不想在该电脑上工作时运行该流程？

像这样

Sub Sample()
    Dim strWarning As String
    Dim Ret

    strWarning = "This process may take sometime. It is advisable to run this " & _
    "when you don't intend to use the pc for sometime. Would you like to Continue?"

    Ret = MsgBox(strWarning, vbYesNo, "Information")

    If Ret <> vbYes Then Exit Sub

    For x = SelectedItems.Count To 1 Step -1

    '~~> Rest of the code
End Sub

HTH

希德