ACC: How to Detect User Idle Time or Inactivity

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Moderate: Requires basic macro, coding, and interoperability skills.


Summary

This article shows you how to create a procedure that will run if your Microsoft Access application does not detect any user input for a specified period of time.


This article assumes that you are familiar with Visual Basic for Applications and with creating Microsoft Access applications using the programming tools provided with Microsoft Access. For more information about Visual Basic for Applications, please refer to the "Building Applications" manual.


NOTE: Visual Basic for Applications (used in Microsoft Access 7.0 and Microsoft Access 97) is called Access Basic in version 2.0.


NOTE: This article explains a technique demonstrated in the sample files, FrmSampl.exe (for Microsoft Access for Windows 95 version 7.0) and FrmSmp97.exe (for Microsoft Access 97). For information about how to obtain these sample files, please see the following articles in the Microsoft Knowledge Base:
150895 ACC95: Microsoft Access Sample Forms Available in Download Center
175066 ACC97: Microsoft Access 97 Sample Forms Available in Download Center

More Information

How to Create the DetectIdleTime Form

  1. Create a blank form that is not based on any table or query and name it DetectIdleTime.
  2. Set the following form properties:
    OnTimer: [Event Procedure]
    TimerInterval: 1000
    NOTE: The TimerInterval setting indicates how often (in milliseconds) the application checks for user inactivity. A setting of 1000 equals 1 second.
  3. Enter the following code for the OnTimer property event procedure:


    NOTE: In the following sample code, an underscore (_) at the end of a line is used as a line-continuation character. Remove the underscore from the end of the line when re-creating this code in Access Basic.

          Sub Form_Timer()
    ' IDLEMINUTES determines how much idle time to wait for before
    ' running the IdleTimeDetected subroutine.
    Const IDLEMINUTES = 5

    Static PrevControlName As String
    Static PrevFormName As String
    Static ExpiredTime

    Dim ActiveFormName As String
    Dim ActiveControlName As String
    Dim ExpiredMinutes

    On Error Resume Next

    ' Get the active form and control name.

    ActiveFormName = Screen.ActiveForm.Name
    If Err Then
    ActiveFormName = "No Active Form"
    Err = 0
    End If

    ActiveControlName = Screen.ActiveControl.Name
    If Err Then
    ActiveControlName = "No Active Control"
    Err = 0
    End If

    ' Record the current active names and reset ExpiredTime if:
    ' 1. They have not been recorded yet (code is running
    ' for the first time).
    ' 2. The previous names are different than the current ones
    ' (the user has done something different during the timer
    ' interval).
    If (PrevControlName = "") Or (PrevFormName = "") _
    Or (ActiveFormName <> PrevFormName) _
    Or (ActiveControlName <> PrevControlName) Then
    PrevControlName = ActiveControlName
    PrevFormName = ActiveFormName
    ExpiredTime = 0
    Else
    ' ...otherwise the user was idle during the time interval, so
    ' increment the total expired time.
    ExpiredTime = ExpiredTime + Me.TimerInterval
    End If

    ' Does the total expired time exceed the IDLEMINUTES?
    ExpiredMinutes = (ExpiredTime / 1000) / 60
    If ExpiredMinutes >= IDLEMINUTES Then
    ' ...if so, then reset the expired time to zero...
    ExpiredTime = 0
    ' ...and call the IdleTimeDetected subroutine.
    IdleTimeDetected ExpiredMinutes
    End If
    End Sub
  4. Create the following procedure in the form module:

           Sub IdleTimeDetected (ExpiredMinutes)
    Dim Msg As String
    Msg = "No user activity detected in the last "
    Msg = Msg & ExpiredMinutes & " minute(s)!"
    MsgBox Msg, 48
    End Sub

How to Use the DetectIdleTime Form

To hide the DetectIdleTime form when the application opens, create the following AutoExec macro:

Macro Name Action
---------------------
AutoExec OpenForm

AutoExec Actions
----------------------------
OpenForm:
Form Name: DetectIdleTime
View: Form
Filter Name:
Where Condition:
Data Mode: Edit
Window Mode: Hidden
You can add code to the IdleTimeDetected procedure so that the procedure runs if there is no user activity for the amount of time specified in the IDLEMINUTES constant value. For example, you could have Microsoft Access quit with the following event procedure:


In Microsoft Access 7.0 and 97:
   Sub IdleTimeDetected (ExpiredMinutes)
Application.Quit acSaveYes
End Sub
In Microsoft Access 2.0:
   Sub IdleTimeDetected (ExpiredMinutes)
Application.Quit A_SAVE
End Sub
This procedure causes Microsoft Access to quit the application, saving all objects without displaying a dialog box.

References

For more information about the Timer event, search the Help Index for
Timer event.
Vlastnosti

ID článku: 128814 - Poslední kontrola: 18. 1. 2007 - Revize: 1

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