监视Window空闲时间

Author:水如烟

示例

Public Class Form1

    Private WithEvents watcher As New LzmTW.uSystem.LastInputWatcher

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        watcher.TimerInterval = 100
        watcher.Start()
    End Sub

    Private Sub watcher_FreeTicks(ByVal ticks As Long) Handles watcher.FreeTicks
        Me.Text = String.Format("空闲时间 {0}", TimeSpan.FromMilliseconds(ticks).ToString)
    End Sub

End Class
代码

Imports System.Runtime.InteropServices

Namespace LzmTW.uSystem
    ''' <summary>
    ''' 监视Window键盘鼠标空闲时间
    ''' </summary>
    ''' <remarks></remarks>
    Public Class LastInputWatcher
        Implements IDisposable

        ''' <param name="ticks">距上次活动结束后的空闲时间。毫秒单位</param>
        Public Event FreeTicks(ByVal ticks As Long)

        Private WithEvents timer As New System.Windows.Forms.Timer

        ''' <summary>
        ''' 监视时钟的间隔。毫秒单位
        ''' </summary>
        Public Property TimerInterval() As Integer
            Get
                Return timer.Interval
            End Get
            Set(ByVal value As Integer)
                timer.Interval = value
            End Set
        End Property

        Public Sub Start()
            timer.Start()
        End Sub

        Public Sub [Stop]()
            timer.Stop()
        End Sub

        Private Sub timer_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles timer.Tick
            RaiseEvent FreeTicks(Win32Native.GetLastInputTime)
        End Sub

        Private disposedValue As Boolean = False

        Protected Overridable Sub Dispose(ByVal disposing As Boolean)
            If Not Me.disposedValue Then
                If disposing Then
                    timer.Dispose()
                End If
            End If
            Me.disposedValue = True
        End Sub

        Public Sub Dispose() Implements IDisposable.Dispose
            Dispose(True)
            GC.SuppressFinalize(Me)
        End Sub

        Private Class Win32Native
            Private Sub New()
            End Sub

            Private Shared pil As LASTINPUTINFO

            Shared Sub New()
                pil.cbSize = Marshal.SizeOf(pil)
            End Sub

            <StructLayout(LayoutKind.Sequential)> _
            Private Structure LASTINPUTINFO
                <MarshalAs(UnmanagedType.U4)> _
                Public cbSize As Integer
                <MarshalAs(UnmanagedType.U4)> _
                Public dwTime As Integer
            End Structure

            <DllImport("user32.dll")> _
            Private Shared Function GetLastInputInfo(ByRef plii As LASTINPUTINFO) As Boolean
            End Function

            Public Shared Function GetLastInputTime() As Long
                If Not GetLastInputInfo(pil) Then Return 0

                Return Environment.TickCount - CType(pil.dwTime, Long)
            End Function
        End Class

    End Class
End Namespace