Microsoft Access 2003 VBA - 登錄表格

這是我第一次嘗試創建登錄表單。我已經閱讀了幾個關於它的論壇，並親自嘗試過。不過，我在嘗試表單時遇到了錯誤。Microsoft Access 2003 VBA - 登錄表格

「運行時錯誤'2001'：您取消了以前的操作。」

這是我的代碼！突出顯示的錯誤是DLOOKUP語句。當我移動光標到LanID，這似乎是0。（我想這有什麼關係呢？）

Option Compare Database 
Option Explicit 

Private intLoginAttempts As Integer 

Private Sub cmdLogin_Click() 
'Check mandatory fields 
If IsNull(Me.txtLanID) Or Me.txtLanID = "" Then 
    MsgBox "Lan ID is required.", vbOKOnly, "Required Data" 
    Me.txtLanID.SetFocus 
    Exit Sub 
End If 

If IsNull(Me.txtPassword) Or Me.txtPassword = "" Then 
    MsgBox "Password is required.", vbOKOnly, "Required Data" 
    Me.txtPassword.SetFocus 
    Exit Sub 
End If 

'Compare input password and database password 
If Me.txtLanID <> "" Then 
    If Me.txtPassword = DLookup("Password", "tblUser", "[LanID]=" & Me.txtLanID) Then 
     LanID = Me.txtLanID 

     'Close Login Page 
     DoCmd.Close acForm, "frmUserLogin", acSaveNo 

     'Check whether user is an admin 
     If Me.txtAdmin = DLookup("Administrator", "tblUser", "[LanID]=" & Me.txtLanID) Then 
     If Me.txtAdmin = -1 Then 
      DoCmd.OpenForm "frmMenu" 
      Else 
       DoCmd.OpenForm "frmBack" 
     End If 
     End If 

    Else 
     MsgBox "Invalid Password. Try again.", vbOKOnly, "Invalid Entry!" 
     Me.txtPassword.SetFocus 
    End If 
End If 

'If user enters incorrect password 3 times 
intLoginAttempts = intLoginAttempts + 1 
If intLoginAttempts = 3 Then 
    MsgBox "You do not have access to the database. Please contact system administrator.", vbCritical, "Restricted Access!" 
    Application.Quit 
End If 
End Sub

來源

2013-01-24 GuessWho

如果tblUser.LanID是文本數據類型，用引號括起來Me.txtLanID以避免錯誤的DLookup()表達式。（你不需要.Value那裏，因爲它是默認屬性。）

DLookup("Password", "tblUser", "[LanID]='" & Me.txtLanID & "'")

如果這還說明，在立即窗口中測試DLookup()表達（與去那裏按Ctrl克 ）來查看它是否拋出錯誤或它返回的值。

請注意，在立即窗口中測試DLookup()時，請使用當前值Me.txtLanID。例如，如果Me.txtLanID包含文本「富」，測試它像這樣...

? DLookup("Password", "tblUser", "[LanID]='foo'")

來源

2013-01-24 07:58:12 HansUp

哦...它說變量沒有在這方面尚未創建... – GuessWho

聽起來像是你試圖用立即窗口中的Me.txtLanID。對不起，我應該預料到那個錯誤。查看更新的答案。 – HansUp

哦！謝謝你的耐心！我試過了，密碼出現在DLookup聲明之後。 – GuessWho

Microsoft Access 2003 VBA - 登錄表格

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