Up to now,I have seen so many
applications that will show system
usage in terms of memory,
processor…But,A user don’t want
this all details. He May expect to
know how much time,he is spending on
each application like browser,Winamp
by the end of day…This application
will help out a user to know how much
time,he is spending on each
application every day. This
application assumes that the window,
which is active as the application on
which the user is working. So,it will
log that application details like
window title,process name and time
spent on it in an xml file. It will
continue like that until the
application is closed. Once the
application is closed,it will show
entire active application’s details in
a browser with proper format.

这是我简单的vb.net版本(我添加了FireFox的声音警报事件)。

创建WinTracker类：

Imports System
Imports System.ComponentModel

Public Class WinTracker
  Implements INotifyPropertyChanged
  Public Event PropertyChanged(ByVal sender As Object,ByVal e As PropertyChangedEventArgs) Implements INotifyPropertyChanged.PropertyChanged
  Public Event SoundAlert(ByVal sender As Object,ByVal e As EventArgs)

  Private _ID As Integer
  Private _Text As String
  Private _ElapsedTime As TimeSpan
  Private _LastStart As DateTime
  Private _RunningTime As TimeSpan

  Public Sub New(ByVal id As Integer,ByVal text As String)
    _ID = id
    _Text = text
    Call StartTracking()
  End Sub

  ReadOnly Property ID() As Integer
    Get
      Return _ID
    End Get
  End Property

  Property Text() As String
    Get
      Return _Text
    End Get
    Set(ByVal value As String)
      If value <> _Text Then
        _Text = value
        RaiseEvent PropertyChanged(Me,New PropertyChangedEventArgs("Text"))
      End If
    End Set
  End Property

  Public Sub StartTracking()
    _RunningTime = TimeSpan.Zero
    _LastStart = DateTime.Now
  End Sub

  Public Sub StopTracking()
    _ElapsedTime += _RunningTime
    _RunningTime = TimeSpan.Zero
    RaiseEvent PropertyChanged(Me,New PropertyChangedEventArgs("ToString"))
  End Sub

  Public Sub UpdateTime()
    _RunningTime = (DateTime.Now - _LastStart)
    RaiseEvent PropertyChanged(Me,New PropertyChangedEventArgs("ToString"))

    If _RunningTime.Seconds >= 60 Then
      RaiseEvent SoundAlert(Me,New EventArgs)
    End If
  End Sub

  Public Overrides Function ToString() As String
    Return "(" & FormatTimeSpan(_ElapsedTime + _RunningTime) & ")   " & _Text
  End Function

  Public Shared Operator =(ByVal thisItem As WinTracker,ByVal thatItem As WinTracker) As Boolean
    Return (thisItem.ID = thatItem.ID)
  End Operator

  Public Shared Operator <>(ByVal thisItem As WinTracker,ByVal thatItem As WinTracker) As Boolean
    Return Not (thisItem.ID = thatItem.ID)
  End Operator

  Private Function FormatTimeSpan(ByVal span As TimeSpan) As String
    Return span.Hours.ToString("00") & " hrs " & span.Minutes.ToString("00") & " min " & span.Seconds.ToString("00") & " sec"
  End Function

  Public Shared Sub SwitchWindows(ByVal FromWindow As WinTracker,ByVal ToWindow As WinTracker)
    FromWindow.StopTracking()
    ToWindow.StartTracking()
  End Sub

End Class

然后创建一个带有计时器和列表框的表单：

Imports System
Imports System.ComponentModel
Imports System.Diagnostics
Imports System.Runtime.InteropServices

Public Class Form1
  Private Declare Auto Function GetForegroundWindow Lib "user32" () As IntPtr
  Private Declare Auto Function GetWindowThreadProcessId Lib "user32" (ByVal hWnd As Int32,ByRef lpdwProcessId As Int32) As UInt32

  Private _Windows As New BindingList(Of WinTracker)
  Private _ActiveWindow As WinTracker

  Private Sub Form1_Load(ByVal sender As Object,ByVal e As EventArgs) Handles MyBase.Load
    With ListBox1
      .ValueMember = "ID"
      .DisplayMember = "ToString"
      .DataSource = New BindingSource(_Windows,Nothing)
    End With
    Timer1.Enabled = True
  End Sub

  Private Sub Timer1_Tick(ByVal sender As Object,ByVal e As EventArgs) Handles Timer1.Tick
    Dim hWnd As Integer = GetForegroundWindow().ToInt32

    If hWnd > 0 Then
      Dim id As Integer = 1
      Call GetWindowThreadProcessId(hWnd,id)
      If id > 0 Then
        Dim text As String = Process.GetProcessById(id).ProcessName

        If text <> String.Empty Then
          Dim spent As WinTracker = _Windows.FirstOrDefault(Function(x As WinTracker) x.ID = id)
          If spent Is Nothing Then
            spent = New WinTracker(id,text)
            _Windows.Add(spent)

            If text.ToLower = "firefox" Then
              AddHandler spent.SoundAlert,AddressOf WinTracker_SoundAlert
            End If

          Else
            spent.Text = text
          End If

          If _ActiveWindow Is Nothing Then
            _ActiveWindow = spent
          Else
            If _ActiveWindow <> spent Then
              WinTracker.SwitchWindows(_ActiveWindow,spent)
              _ActiveWindow = spent
            Else
              _ActiveWindow.UpdateTime()
            End If
          End If

        End If
      End If
    End If
  End Sub

  Private Sub WinTracker_SoundAlert(ByVal sender As Object,ByVal e As EventArgs)
    My.Computer.Audio.PlaySystemSound(Media.SystemSounds.Beep)
  End Sub    

End Class

根据需要重构。