【C#/WPF】用System.Timers.Timer计时器做浮窗广告

需求：鼠标静止一段时间后，显示浮窗广告。

思路：界面XAML写好一个专门显示浮窗广告的Canvas，先设为不可见Visibility=”Collapsed”，然后用System.Timers.Timer类做计时器，设置该timer每秒钟重复运行一次（检测一次），给计数器自增并判断是否累计达到要显示广告的时间，要显示则修改为Visibility=”Visible”。界面绑定鼠标的移动事件为重置该计数器。广告右上角是关闭按钮，点击按钮修改回Visibility=”Collapsed”即可。

关键代码如下：

前台：

<!-- 浮窗广告：主界面鼠标静止一段时间后，显示该广告 -->
<Canvas x:Name="adCanvas" Width="400" Height="200" Visibility="Collapsed">
    <!-- 关闭按钮 -->
    <Button Command="{Binding CloseAdCanvasCommand}" Canvas.Right="0" Canvas.Top="0">
        <Image Source="/项目名;component/Presentation/Resources/Images/tool.png" />
    </Button>
</Canvas>

控制层关键代码

// 静止多少秒显示广告，写在了配置文件里
float adIntervalTime = float.Parse(ConfigurationManager.AppSettings["AD_WINDOW_INTERVAL_TIME"]);

#region 一段时间鼠标静止，浮窗广告
// 主界面鼠标移动事件。一段时间鼠标不移动，则浮窗广告
private void MouseMoveCommand()
{
    adStopTime = 0; // 重置计时器
}

// 开始浮窗广告的计时
private void StartAdWindowTimer()
{
    Timer timer = new Timer();
    timer.Elapsed += new ElapsedEventHandler(TimerTick);
    timer.Interval = 1000; // 每1秒重复检测一次
    timer.Enabled = true;
}

// 计算是否要显示浮窗广告
private void TimerTick(object sender, EventArgs e)
{
    adStopTime++;
    if (adStopTime >= adIntervalTime && allowADShow)
    {
        adCanvasChangeVisibility(true);
        allowADShow = false;
    }
}

// 改变浮窗广告Canvas的显隐
private void adCanvasChangeVisibility(bool visible)
{
    App.Current.Dispatcher.Invoke((Action)delegate // <--- HERE
    {
        if (visible)
            adCanvas.Visibility = Visibility.Visible;
        else
            adCanvas.Visibility = Visibility.Collapsed;
    });
}

// 初始化浮窗广告
private void InitAdCanvas()
{
    adCanvas = shellWindow.adCanvas;
    adCanvasChangeVisibility(false);

    // 背景是广告图片
    ImageBrush brush = new ImageBrush();
    brush.ImageSource = new BitmapImage(new Uri("pack://application:,,,/项目名;component/Presentation/Resources/Images/logo.jpg"));
    adCanvas.Background = brush;
}

// 关闭浮窗广告
private void CloseAdCanvasCommand()
{
    adCanvasChangeVisibility(false);
    allowADShow = true;
}
#endregion

---

资料参考MSDN中System.Timers.Timer类的使用：

• https://msdn.microsoft.com/query/dev14.query?appId=Dev14IDEF1&l=EN-US&k=k(System.Timers.Timer);k(TargetFrameworkMoniker-.NETFramework,Version%3Dv4.5);k(DevLang-csharp)&rd=true

2018.3.12更新：

另一种思路，用AutoResetEvent控制线程的阻塞、唤醒。

private void TestTimer()
{
    AutoResetEvent autoResetEvent = new AutoResetEvent(false);
    int limit = ;
    int index = ;
    while (!autoResetEvent.WaitOne(TimeSpan.FromSeconds())) // 每隔3秒钟执行一次循环体
    {
        index++;
        Console.WriteLine("index = " + index);
        if (index >= limit)
        {
            autoResetEvent.Set(); // 跳出循环体
        }
    }

    Console.WriteLine("Thread got signal");
}

参考：

• http://blog.csdn.net/hejingyuan6/article/details/39700499
• http://blog.csdn.net/theoldfuture/article/details/52420913
• https://www.cnblogs.com/jicheng/articles/5998244.html
• https://www.cnblogs.com/czytcn/p/8085071.html
• https://docs.microsoft.com/zh-cn/dotnet/api/system.threading.waithandle.waitone?f1url=https%3A%2F%2Fmsdn.microsoft.com%2Fquery%2Fdev15.query%3FappId%3DDev15IDEF1%26l%3DZH-CN%26k%3Dk(System.Threading.WaitHandle.WaitOne);k(TargetFrameworkMoniker-.NETFramework&view=netframework-4.7.1