如何設定Access中訊息框的顯示次數限制

我已將登錄表單添加到 Access 資料庫。我試圖找出一種方法來限制用戶輸入錯誤密碼的次數。在如下所示的 VBA 代碼中，當用戶輸入的密碼不正確時，會觸發以下訊息框，“MsgBox “密碼錯誤”，vbOKOnly vbExclamation。

我希望用戶在出現不同的訊息框之前獲得三次失敗的嘗試。諸如“請聯系管理員”之類的...

在此先感謝您的幫助。

Private Sub OkBTN_Click()

        'Check that User is selected
    If IsNull(Me.cboUser) Then
        MsgBox "You forgot to select your name from the drop down menu!", vbCritical
        Me.cboUser.SetFocus
    Else
        
    'Check for correct password
    If Me.txtPassword = Me.cboUser.Column(2) Then
        
    'Check if password needs to be reset
    If Me.cboUser.Column(4) Then
        DoCmd.OpenForm "frmPasswordChange", , , "[UserID] = " & Me.cboUser
    End If

        Me.Visible = False
        Else
        MsgBox "Incorrect password", vbOKOnly   vbExclamation
        
        Me.txtPassword = Null
        Me.txtPassword.SetFocus
        End If
    End If

End Sub

uj5u.com熱心網友回復：

在這種情況下，我想我會宣告一個Static計數器變數。靜態變數的值在程序呼叫之間保留。其他替代方法是將計數存盤在全域變數中、使用 TempVar 或將它們寫入表中。

Private Sub OkBTN_Click()

    Static intIncorrectCount As Integer ' The value of a static variable is preserved between procedure calls.

    'Check that User is selected
    If IsNull(Me.cboUser) Then
        MsgBox "You forgot to select your name from the drop down menu!", vbCritical
        Me.cboUser.SetFocus
    Else

        'Check for correct password
        If Me.txtPassword = Me.cboUser.Column(2) Then

            'Check if password needs to be reset
            If Me.cboUser.Column(4) Then
                DoCmd.OpenForm "frmPasswordChange", , , "[UserID] = " & Me.cboUser
            End If
            Me.Visible = False
            intIncorrectCount = 0
            
        ElseIf intIncorrectCount > 2 Then
            MsgBox "Too many incorrect attempts.  Closing Access.", vbOKOnly   vbExclamation
            'DoCmd.Quit ' ### Save your code before enabling this line.  ###
            
        Else
            MsgBox "Incorrect password", vbOKOnly   vbExclamation

            Me.txtPassword = Null
            Me.txtPassword.SetFocus
            intIncorrectCount = intIncorrectCount   1
        End If
    End If

End Sub

uj5u.com熱心網友回復：

好的，謝謝本。我做了一些更改，現在出現錯誤，“編譯錯誤：否則沒有 if”。我想我把事情搞砸了，但我很難把它找回來。

Private Sub OkBTN_Click()
Static intIncorrectCount As Integer
Dim AuthorityNumber As Integer
'Dim rs As Recordset

'Column definitions
'UserID = 0
'FullName = 1
'Password = 2
'PWReset = 3
'AccessLevelID = 4

'Set rs = CurrentDb.OpenRecordset("UserNameQuery", dbOpenSnapshot)

'N = Nz(DLookup("Fullname", "UserNameQuery", "Fullname=""" & Me.cboUser & """"), " ")


If IsNull(Me.cboUser) Then 'Check that User is selected
    MsgBox "You forgot to select your name from the drop down menu!", vbCritical
    Me.cboUser.SetFocus
Else
    
If Me.txtPassword = Me.cboUser.Column(2) Then 'Check for correct password
If Me.cboUser.Column(3) Then 'Check if password needs to be reset
    DoCmd.OpenForm "frmPasswordChange", , , "[UserID] = " & Me.cboUser
End If

If Me.cboUser.Column(4) Then
    DoCmd.OpenForm "SRL1MainMenu"
    Forms!SRL1MainMenu!FullNameLoggedIn = Forms!frmLogin!cboUser.Column(1)
Else
    DoCmd.OpenForm "L2MainMenu2"
    Forms!L2MainMenu2!FullNameLoggedIn = Forms!frmLogin!cboUser.Column(1)
    
ElseIf intIncorrectCount > 1 Then
    MsgBox "Too many failed login attempts. Click OK to set new password", vbOK   vbExclamation
    DoCmd.OpenForm "frmPasswordChange", , , "[UserID] = " & Me.cboUser
    'DoCmd.Close acForm, "frmLogin"
    Else
    MsgBox "Incorrect password", vbOKOnly   vbExclamation
    
    Me.Visible = False
    intIncorrectCount = 0

    Me.txtPassword = Null
    Me.txtPassword.SetFocus
    intIncorrectCount = intIncorrectCount   1
    End If
End If
    TempVars("Username") = Me.cboUser.Value
End If

End If
End Sub

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