WPF 不活动和活动

Question

我正在尝试处理 WPF 应用程序中的用户不活动和活动以淡入淡出一些内容。经过大量研究，我决定采用（至少在我看来）Hans Passant 发布的非常优雅的解决方案 here。

只有一个缺点：只要光标停留在窗口顶部，PreProcessInput 事件就会持续触发。我有一个全屏应用程序，所以这会杀死它。任何我如何绕过这种行为的想法都将不胜感激。

public partial class MainWindow : Window
{
    readonly DispatcherTimer activityTimer;

    public MainWindow()
    {
        InitializeComponent();

        InputManager.Current.PreProcessInput += Activity;

        activityTimer = new DispatcherTimer
        {
            Interval = TimeSpan.FromSeconds(10),
            IsEnabled = true
        };
        activityTimer.Tick += Inactivity;
    }

    void Inactivity(object sender, EventArgs e)
    {
        rectangle1.Visibility = Visibility.Hidden; // Update
        // Console.WriteLine("INACTIVE " + DateTime.Now.Ticks);
    }

    void Activity(object sender, PreProcessInputEventArgs e)
    {
        rectangle1.Visibility = Visibility.Visible; // Update
        // Console.WriteLine("ACTIVE " + DateTime.Now.Ticks);

        activityTimer.Stop();
        activityTimer.Start();
    }
}

更新

我可以更好地缩小所描述的行为（请参阅上述代码中的 rectangle1.Visibility 更新）。只要光标停留在窗口顶部并且例如更改控件的Visibility，就会引发PreProcessInput。也许我误解了PreProcessInput 事件的目的以及它何时触发。 MSDN 在这里不是很有帮助。

Answer 1

我们对我们的软件也有类似的需求...它也是一个 WPF 应用程序，并且作为一项安全功能 - 客户端可以配置其用户空闲时注销的时间。

下面是我用来包装空闲检测代码的类（它利用内置的 Windows 功能）。

我们只是每 1 秒有一个计时器滴答来检查空闲时间是否大于指定的阈值...占用 0 CPU。

首先，代码的使用方法如下：

var idleTime = IdleTimeDetector.GetIdleTimeInfo();

if (idleTime.IdleTime.TotalMinutes >= 5)
{
    // They are idle!
}

您可以使用它并确保您的 WPF 全屏应用“专注”以满足您的需求：

using System;
using System.Runtime.InteropServices;

namespace BlahBlah
{
    public static class IdleTimeDetector
    {
        [DllImport("user32.dll")]
        static extern bool GetLastInputInfo(ref LASTINPUTINFO plii);

        public static IdleTimeInfo GetIdleTimeInfo()
        {
            int systemUptime = Environment.TickCount,
                lastInputTicks = 0,
                idleTicks = 0;

            LASTINPUTINFO lastInputInfo = new LASTINPUTINFO();
            lastInputInfo.cbSize = (uint)Marshal.SizeOf(lastInputInfo);
            lastInputInfo.dwTime = 0;

            if (GetLastInputInfo(ref lastInputInfo))
            {
                lastInputTicks = (int)lastInputInfo.dwTime;

                idleTicks = systemUptime - lastInputTicks;
            }

            return new IdleTimeInfo
            {
                LastInputTime = DateTime.Now.AddMilliseconds(-1 * idleTicks),
                IdleTime = new TimeSpan(0, 0, 0, 0, idleTicks),
                SystemUptimeMilliseconds = systemUptime,
            };
        }
    }

    public class IdleTimeInfo
    {
        public DateTime LastInputTime { get; internal set; }

        public TimeSpan IdleTime { get; internal set; }

        public int SystemUptimeMilliseconds { get; internal set; }
    }

    internal struct LASTINPUTINFO
    {
        public uint cbSize;
        public uint dwTime;
    }
}

Answer 2

我可以弄清楚是什么导致了所描述的行为。

例如，当控件的Visibility 发生更改时，PreProcessInput 事件将引发PreProcessInputEventArgs.StagingItem.Input 类型为InputReportEventArgs。

可以通过在OnActivity 事件中过滤MouseEventArgs 和KeyboardEventArgs 类型的InputEventArgs 来避免这种行为，并验证是否没有按下鼠标按钮并且光标的位置仍然与应用程序变为非活动状态。

public partial class MainWindow : Window
{
    private readonly DispatcherTimer _activityTimer;
    private Point _inactiveMousePosition = new Point(0, 0);

    public MainWindow()
    {
        InitializeComponent();

        InputManager.Current.PreProcessInput += OnActivity;
        _activityTimer = new DispatcherTimer { Interval = TimeSpan.FromMinutes(5), IsEnabled = true };
        _activityTimer.Tick += OnInactivity;
    }

    void OnInactivity(object sender, EventArgs e)
    {
        // remember mouse position
        _inactiveMousePosition = Mouse.GetPosition(MainGrid);

        // set UI on inactivity
        rectangle.Visibility = Visibility.Hidden;
    }

    void OnActivity(object sender, PreProcessInputEventArgs e)
    {
        InputEventArgs inputEventArgs = e.StagingItem.Input;

        if (inputEventArgs is MouseEventArgs || inputEventArgs is KeyboardEventArgs)
        {
            if (e.StagingItem.Input is MouseEventArgs)
            {
                MouseEventArgs mouseEventArgs = (MouseEventArgs)e.StagingItem.Input;

                // no button is pressed and the position is still the same as the application became inactive
                if (mouseEventArgs.LeftButton == MouseButtonState.Released &&
                    mouseEventArgs.RightButton == MouseButtonState.Released &&
                    mouseEventArgs.MiddleButton == MouseButtonState.Released &&
                    mouseEventArgs.XButton1 == MouseButtonState.Released &&
                    mouseEventArgs.XButton2 == MouseButtonState.Released &&
                    _inactiveMousePosition == mouseEventArgs.GetPosition(MainGrid))
                    return;
            }

            // set UI on activity
            rectangle.Visibility = Visibility.Visible;

            _activityTimer.Stop();
            _activityTimer.Start();
        }
    }
}

Answer 3

我在 IdleDetector 类中实现了该解决方案。我已经改进了一点代码。空闲检测器抛出一个可以被拦截的 IsIdle ！它给了！我等一些cmets。

public class IdleDetector
{
    private readonly DispatcherTimer _activityTimer;
    private Point _inactiveMousePosition = new Point(0, 0);

    private IInputElement _inputElement;
    private int _idleTime = 300;

    public event EventHandler IsIdle;

    public IdleDetector(IInputElement inputElement, int idleTime)
    {
        _inputElement = inputElement;
        InputManager.Current.PreProcessInput += OnActivity;
        _activityTimer = new DispatcherTimer { Interval = TimeSpan.FromSeconds(idleTime), IsEnabled = true };
        _activityTimer.Tick += OnInactivity;
    }

    public void ChangeIdleTime(int newIdleTime)
    {
        _idleTime = newIdleTime;

        _activityTimer.Stop();
        _activityTimer.Interval = TimeSpan.FromSeconds(newIdleTime);
        _activityTimer.Start();
    }

    void OnInactivity(object sender, EventArgs e)
    {
        _inactiveMousePosition = Mouse.GetPosition(_inputElement);
        _activityTimer.Stop();
        IsIdle?.Invoke(this, new EventArgs());
    }

    void OnActivity(object sender, PreProcessInputEventArgs e)
    {
        InputEventArgs inputEventArgs = e.StagingItem.Input;

        if (inputEventArgs is MouseEventArgs || inputEventArgs is KeyboardEventArgs)
        {
            if (e.StagingItem.Input is MouseEventArgs)
            {
                MouseEventArgs mouseEventArgs = (MouseEventArgs)e.StagingItem.Input;

                // no button is pressed and the position is still the same as the application became inactive
                if (mouseEventArgs.LeftButton == MouseButtonState.Released &&
                    mouseEventArgs.RightButton == MouseButtonState.Released &&
                    mouseEventArgs.MiddleButton == MouseButtonState.Released &&
                    mouseEventArgs.XButton1 == MouseButtonState.Released &&
                    mouseEventArgs.XButton2 == MouseButtonState.Released &&
                    _inactiveMousePosition == mouseEventArgs.GetPosition(_inputElement))
                    return;
            }

            _activityTimer.Stop();
            _activityTimer.Start();
        }
    }
}

Answer 4

你试过PreviewMouseMove而不是听PreProcessInput吗？