How to detect User Idle Time or Inactivity in Access 2000

This article applies to a Microsoft Access database (.mdb) and to a Microsoft Access project (.adp).


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


IN THIS TASK

Summary

This article shows you how to create a procedure that will run if your Access application does not detect any user input for a specified period of time. It involves creating a hidden form containing code that keeps count of idle time.

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements.

Note Using this code to add records to a table when a database is idle may result in excessive memory consumption.

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. Set the OnTimer property to the following event procedure:
    Sub Form_Timer()
    ' IDLEMINUTES determines how much idle time to wait for before
    ' running the IdleTimeDetected subroutine.
    Const IDLEMINUTES = 1

    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 Action Arguments
----------------------------
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 Access quit with the following event procedure:

Sub IdleTimeDetected (ExpiredMinutes)
Application.Quit acSaveYes
End Sub
This procedure causes Access to quit the application, saving all objects without displaying a dialog box.




References

For more information about the Timer event, in the Visual Basic Editor, click Microsoft Visual Basic Help on the Help menu, type Timer event in the Office Assistant or the Answer Wizard, and then click Search to view the topic.












Svojstva

ID članka: 210297 - posljednja izmjena: 28. tra 2009. - verzija: 1

Povratne informacije