NETCF开发之比较两种Timer类

如果要求线程按照规定的时间间隔周期性地执行的话,可以使用Timer类将需要调用的方法加入队列等待周期性执行。Timer类包含在System.Threading命名空间。Timer类通过系统提供的线程池线程在每次计时器期满时运行计时器委托。因为System.Threading.Timer对象是在单独的线程中执行,因此在退出应用程序之前需要完全终止计时器。

.NET Compact Framework中的其他Timer类,比如System.Windows.Forms命名空间的Timer类与System.Threading命名空间的Timer类有所不同。System.Windows.Forms.Timer类每次计时器期满时产生WM_TIMER系统消息来触发事件,不能使用单独的线程来执行。System.Windows.Forms.Timer类使用简单且适合用于周期性的更新用户界面。如果需要高精度的计时器,则应该使用System.Threading.Timer

23-3展示了使用不同Timer类的精确程度比较。在如图23-3所示的应用程序中分别创建了System.Threading.TimerSystem.Windows.Forms.Timer实例,并设置时间间隔为100毫秒。

NETCF开发之比较两种Timer类

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23-3:不同Timer类的精确性比较

这个TimerDemo应用程序测量不同Timer类的平均时间间隔。当点击“模拟界面操作”按钮时,应用程序产生一个额外的处理活动,使不同Timer类在行为上的差别更加清晰明显。Windows.Forms.Timer对象从消息队列接收到一个WM_TIMER消息时调用它自己的委托。Windows.Forms.Timer是单线程组件,精度限定为55毫秒。当应用程序处理繁忙时,时间间隔小于55毫秒的WM_TIMER消息会被忽略。换句话说,由于Windows.Forms.Timer的精度限制,消息队列中不能存在超过一个未处理的WM_TIMER消息,否则多余的WM_TIMER消息会重叠合并,因而丢失计时信号。而在图23-3中正确的做法是,Threading.Timer对象运行在一个单独的线程中,计时器的间隔时间一到则随时被运行。Threading.Timer对象负责处理精确度(两个Timer类的处理次数),因为“模拟界面操作”按钮被点击后,主线程的优先级被临时降低,以此模拟应用程序处于繁忙状态。清单23-7说明了TimerDemo应用程序的实现代码。

清单23-7TimerDemo应用程序实现代码

<group id="_x0000_s1032" style="WIDTH: 414pt; HEIGHT: 460.2pt; mso-position-horizontal-relative: char; mso-position-vertical-relative: line" coordsize="7200,8022" coordorigin="2526,7642" editas="canvas"><lock aspectratio="t" v:ext="edit"></lock><shape id="_x0000_s1033" style="LEFT: 2526px; WIDTH: 7200px; POSITION: absolute; TOP: 7642px; HEIGHT: 8022px" o:preferrelative="f" type="#_x0000_t75"><font size="3"><fill o:detectmouseclick="t"></fill><path o:connecttype="none" o:extrusionok="t"></path><lock v:ext="edit" text="t"></lock></font></shape><rect id="_x0000_s1034" style="LEFT: 2526px; WIDTH: 7200px; POSITION: absolute; TOP: 7642px; HEIGHT: 8022px" strokecolor="#eaeaea" fillcolor="#eaeaea"><textbox style="mso-next-textbox: #_x0000_s1034"><table cellspacing="0" cellpadding="0" width="100%"><tbody><tr> <td style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent"> <div> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">Public Class TimerDemo<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><p><font face="Times New Roman"></font></p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span>Private threadingTimer As Threading.Timer<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span>Private prevTimerTicks As Long<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span>Private avgTimerTicks As Long<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span>Private numTimerExpirations As Long<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span>Private timerRunning As Boolean = False<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><p><font face="Times New Roman"></font></p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span>Private Sub btnThreadingTimer_Click(ByVal sender As System.Object, _<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">ByVal e As System.EventArgs) Handles btnThreadingTimer.Click<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 21pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">If timerRunning = True Then<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">timerRunning = False<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">While Not threadingTimer Is Nothing<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 63pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">Threading.Thread.Sleep(0)<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">End While<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">avgTimerTicks = avgTimerTicks / numTimerExpirations<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>lThreadingTimer.Text = "Avg. Timer Interval: " + avgTimerTicks.ToString() + _<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 63pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">" ms (" + numTimerExpirations.ToString() + ")"<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>btnThreadingTimer.Text = "Start Threading Timer"<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>btnFormsTimer.Enabled = True<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-spacerun: yes"></span><span style="mso-tab-count: 1"> </span>Else<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>timerRunning = True<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>lThreadingTimer.Text = "Timer running"<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>btnThreadingTimer.Text = "Stop Threading Timer"<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>btnFormsTimer.Enabled = False<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>avgTimerTicks = 0<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>numTimerExpirations = 0<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>prevTimerTicks = Environment.TickCount<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>threadingTimer = New Threading.Timer(New _<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 63pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">Threading.TimerCallback(AddressOf ThreadingTimerTick), Nothing, 0, 100)<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>End If<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span>End Sub<p></p></font></span></p> </div> </td> </tr></tbody></table></textbox></rect><wrap type="none"></wrap><anchorlock></anchorlock></group>

<group id="_x0000_s1029" style="WIDTH: 414pt; HEIGHT: 624pt; mso-position-horizontal-relative: char; mso-position-vertical-relative: line" coordsize="7200,10877" coordorigin="2526,7642" editas="canvas"><lock aspectratio="t" v:ext="edit"></lock><shape id="_x0000_s1030" style="LEFT: 2526px; WIDTH: 7200px; POSITION: absolute; TOP: 7642px; HEIGHT: 10877px" o:preferrelative="f" type="#_x0000_t75"><font size="3"><font face="Times New Roman"><fill o:detectmouseclick="t"></fill><path o:connecttype="none" o:extrusionok="t"></path><lock v:ext="edit" text="t"></lock></font></font></shape><rect id="_x0000_s1031" style="LEFT: 2526px; WIDTH: 7200px; POSITION: absolute; TOP: 7642px; HEIGHT: 10877px" strokecolor="#eaeaea" fillcolor="#eaeaea"><textbox style="mso-next-textbox: #_x0000_s1031"><table cellspacing="0" cellpadding="0" width="100%"><tbody><tr> <td style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent"> <div> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">Private Sub btnFormsTimer_Click(ByVal sender As System.Object, _<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">ByVal e As System.EventArgs) Handles btnFormsTimer.Click<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 21pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">If timerRunning = True Then<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">timerRunning = False<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><p><font face="Times New Roman"></font></p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>avgTimerTicks = avgTimerTicks / numTimerExpirations<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>lFormsTimer.Text = "Avg. Timer Interval: " + avgTimerTicks.ToString() + _<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 63pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">" ms (" + numTimerExpirations.ToString() + ")"<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>btnFormsTimer.Text = "Start Forms Timer"<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>btnThreadingTimer.Enabled = True<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>Else<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>timerRunning = True<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>lFormsTimer.Text = "Timer running"<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>btnFormsTimer.Text = "Stop Forms Timer"<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>btnThreadingTimer.Enabled = False<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>avgTimerTicks = 0<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>numTimerExpirations = 0<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>prevTimerTicks = Environment.TickCount<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>formsTimer.Interval = 100<span style="mso-spacerun: yes"> </span>' </font></span><span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">利用窗体上放置的</span><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">Timer</font></span><span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">控件</span><span lang="EN-US" style="FONT-SIZE: 9pt"><p></p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>formsTimer.Enabled = True<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>End If<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">End Sub<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><p><font face="Times New Roman"></font></p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">Private Sub btnProcessing_Click(ByVal sender As System.Object, _<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">ByVal e As System.EventArgs) Handles btnProcessing.Click<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>btnProcessing.Enabled = False<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>Threading.Thread.CurrentThread.Priority = Threading.ThreadPriority.BelowNormal<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>For i As Long = 0 To 5000000<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>Next<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>btnProcessing.Enabled = True<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>Threading.Thread.CurrentThread.Priority = Threading.ThreadPriority.Normal<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"></span>End Sub<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><p><font face="Times New Roman"></font></p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"></span>Private Sub ThreadingTimerTick(ByVal state As Object)<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>If timerRunning = False Then<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>threadingTimer.Dispose()<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>threadingTimer = Nothing<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>Else<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>Dim currentTimerTicks As Long = Environment.TickCount<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>avgTimerTicks = avgTimerTicks + (currentTimerTicks - prevTimerTicks)<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>numTimerExpirations = numTimerExpirations + 1<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>prevTimerTicks = currentTimerTicks<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>End If<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 14pt; mso-line-height-rule: exactly"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"></span>End Sub<p></p></font></span></p> </div> </td> </tr></tbody></table></textbox></rect><wrap type="none"></wrap><anchorlock></anchorlock></group>

<group id="_x0000_s1026" style="WIDTH: 414pt; HEIGHT: 226.2pt; mso-position-horizontal-relative: char; mso-position-vertical-relative: line" coordsize="7200,3943" coordorigin="2526,7642" editas="canvas"><lock aspectratio="t" v:ext="edit"></lock><shape id="_x0000_s1027" style="LEFT: 2526px; WIDTH: 7200px; POSITION: absolute; TOP: 7642px; HEIGHT: 3943px" o:preferrelative="f" type="#_x0000_t75"><font size="3"><font face="Times New Roman"><fill o:detectmouseclick="t"></fill><path o:connecttype="none" o:extrusionok="t"></path><lock v:ext="edit" text="t"></lock></font></font></shape><rect id="_x0000_s1028" style="LEFT: 2526px; WIDTH: 7200px; POSITION: absolute; TOP: 7642px; HEIGHT: 3943px" strokecolor="#eaeaea" fillcolor="#eaeaea"><textbox style="mso-next-textbox: #_x0000_s1028"><table cellspacing="0" cellpadding="0" width="100%"><tbody><tr> <td style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent"> <div> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">Private Sub formsTimer_Tick(ByVal sender As System.Object, _<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: 21pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">ByVal e As System.EventArgs) Handles formsTimer.Tick<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">If timerRunning = False Then<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: 21pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">formsTimer.Enabled = False<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>formsTimer = Nothing<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>Else<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>Dim currentTimerTicks As Long = Environment.TickCount<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>avgTimerTicks = avgTimerTicks + (currentTimerTicks - prevTimerTicks)<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>numTimerExpirations = numTimerExpirations + 1<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>prevTimerTicks = currentTimerTicks<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"> </span>End If<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman"><span style="mso-spacerun: yes"> </span><span style="mso-tab-count: 1"></span>End Sub<p></p></font></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><p><font face="Times New Roman"></font></p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-SIZE: 9pt"><font face="Times New Roman">End Class<p></p></font></span></p> </div> </td> </tr></tbody></table></textbox></rect><wrap type="none"></wrap><anchorlock></anchorlock></group>

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