如何退出“do while”語句

Question

Sub FindValue()

Dim firstAddress As String
Dim Expense As String
Dim rRange As Range
Dim FirstrngFnd As Range
Dim x As Integer
Dim y As Integer
Dim z As Integer

Workbooks.Open FileName:= _
    "D:\My Documents\Excel Files\AA Credit Card\1008.xlsx"        'A worksheet with several columns - Column G (Column 7) is a list of "expenses".  
Workbooks.Open FileName:= _
    "D:\My Documents\Excel Files\Credit Card Analysis.xlsx"       'A worksheet with "expenses" listed in random order in Column A (Column1)
Windows("Credit Card Analysis.xlsx").Activate
ActiveWindow.Panes(1).Activate

Expense = Application.InputBox("Select the required expense from Column A")     'Pick an "expense" from a list in Column A

'Open the first file in the first folder
Windows("1008.xlsx").Activate
ActiveWindow.Panes(1).Activate

'Establish the first and last rows in Column A (which contain a list of dates by increasing date): required to establish the search range
Set rRange = Range("A1", Cells(Rows.Count, 1).End(xlUp))
    For Each rCell In rRange
        If IsDate(rCell) Then
            rCell(2, 1).Select
    Exit For
        End If
    Next rCell

x = (ActiveCell.Row - 1)                          'This finds the FIRST row in the file with a date in it
y = Cells(Rows.Count, 1).End(xlUp).Row            'This finds the LAST row in the file with a date in it
My_Workbook = ActiveWorkbook.Name                                               'Holds the current Workbook name

'Move over to the "analysis" column (G) (Column 7)
With Worksheets(1).Range(Cells(x, 7), Cells(y, 7))
    Set FirstrngFnd = .Find(Expense, LookIn:=xlValues, LookAt:=xlPart)          'Finds the first occurrence of "expense"
        If Not FirstrngFnd Is Nothing Then                                      'if the "expense" isn't listed then goto Line400
            firstAddress = FirstrngFnd.Address
        Do           'DO WHATEVER IS REQUIRED IN THIS SECTION: FROM "DO" TO "Set FirstrngFnd = .FindNext(FirstrngFnd)"
            z = FirstrngFnd.Row
            FirstrngFnd.Value = "Mike"        'IF YOU OMIT THIS LINE THEN ALL THE VALUES REMAIN AT "expense", SO THE PROGRAM JUST GOES ROUND (AND ROUND) AGAIN.
            Set FirstrngFnd = .FindNext(FirstrngFnd)
        Loop While Not FirstrngFnd Is Nothing
    End If
End With
End Sub

如果我刪除 "FirstrngFnd.Value = "Mike" 行，那么 Golumn G 中的值永遠不會改變，所以當程序到達文件末尾時，它會再次循環。

我怎樣才能讓它識別出它已經通過文件一次，然后繼續前進？

Answer 1

請修改：

Loop While Not FirstrngFnd Is Nothing

這樣：

Loop While Not FirstrngFnd Is Nothing And FirstrngFnd.Address <> firstAddress 

Answer 2

在無限循環中查找

• 這涵蓋了當您使用Find方法（包括FIndNext ）查找范圍內所有出現的值，但您不想更改它們並且您也不想最終陷入無限循環的情況.
• 為簡化起見，程序使用Sheet1 (CodeName) 和范圍“A1:A3”和“是”作為標准。
• 將它們復制到新工作簿中。
• 首先測試兩個沒有值的過程，然后在單元格中輸入一些“是”值（沒有雙引號）。 您還可以將范圍更改為例如A1:A10 ，以便更好地理解。

編碼

Option Explicit

' To exit the endless loop, press and hold down the ESC key.
Sub testEndlessLoop()
    
    Dim rng As Range
    Dim cel As Range
    
    Set rng = Sheet1.Range("A1:A3")
    Set cel = rng.Find( _
        What:="Yes", _
        After:=rng(rng.Cells.Count), _
        LookIn:=xlFormulas)
    
    ' Assuring that a cel containing "Yes" has been found. Once it has
    ' been found, find will always find an occurrence of "Yes" whether
    ' there is one, two or three occurrences in the range,
    ' which will result in an endless loop (Do Loop).
    If Not cel Is Nothing Then
        ' A cell containing "Yes" has been found.
        
        Do
            MsgBox "Found ""Yes"" in cell '" & cel.Address & "'."
            ' Find the next occurrence of "Yes"
            Set cel = rng.FindNext(cel)

        ' 'While Not cel Is Nothing' is redundant because 'cel' will
        ' never be 'Nothing' anyway, which is ensured previously with
        ' 'If Not cel Is Nothing Then'.
        Loop While Not cel Is Nothing
    
    Else
        ' A cell containing "Yes" has not been found.
        MsgBox "No occurrences found."
    End If

End Sub

Sub testWorkingLoop()
    
    Dim rng As Range
    Dim cel As Range
    Dim FirstAddress As String
    
    Set rng = Sheet1.Range("A1:A3")
    Set cel = rng.Find( _
        What:="Yes", _
        After:=rng(rng.Cells.Count), _
        LookIn:=xlFormulas)
    
    If Not cel Is Nothing Then
        ' A cell containing "Yes" has been found.

        ' Write the range address of the first found occurrence to a variable.
        FirstAddress = cel.Address
        
        Do
            ' This is where you do stuff when "Yes" is found.
            
            MsgBox "Found ""Yes"" in cell '" & cel.Address & "'."
            ' Most often you don't want to change the found cell,
            ' but you want to change another cell in the same row,
            ' e.g. write to the cell in column 'B'.
            cel.Offset(0, 1).Value = "Found a ""Yes""."
            
            ' This is where you do stuff when "Yes" is found.
            
            ' Find the next occurrence of "Yes"
            Set cel = rng.FindNext(cel)
        
        ' Again, 'cel' will never be 'Nothing'.
        Loop While cel.Address <> FirstAddress
    
    Else
        ' A cell containing "Yes" has not been found.
        MsgBox "No occurrences found."
    End If

End Sub