创建窗口-弹出窗口

Question

所谓窗口弹出，我指的是弹出窗口，它只停留在窗口/应用程序中。据我所知，我必须显式处理弹出窗口的显示/隐藏。

应用程序.当前.激活/停用

Application.Current.MainWindow.Activated/Deactivated

激活/停用

我想确保Alt隐藏/显示弹出窗口，win-D隐藏弹出，在同一应用程序中切换窗口不应该做任何事情，从任务栏恢复/最大化应该显示弹出。

我已经为所有这些事件编写了处理程序，他们正在杀死我，为什么这是一个令人恼火的问题。必须有一个简单的方法来处理这件事。有什么想法吗？

Answer 1

一个事件处理程序应该足以完成整个任务。

首先，在App.xaml中添加使用附加属性设置事件处理程序的窗口样式：

<Style TargetType="Window">
  <Setter Property="local:PopupWindowControl.AttachHandler" Value="true" />
</Style>

标记所有需要特殊行为的窗口：

<Window local:PopupWindowControl.HideWhenAppInactive="true" ... >

现在只需要创建附加的属性和更新方法。

• "HideWhenAppInactive“是一个bool附加属性，用于标记Windows和弹出窗口。它还维护有此属性的所有弹出窗口的记录，set.
• "AttachHandler“是一个带有PropertyChangedCallback的bool附加属性，它是一种更新handler.
• "Update”可见性的方法，并根据是否存在可见和活动窗口

来更新弹出窗口。

看起来会是这样的：

public class PopupWindowControl : DependencyObject
{
  // HideWhenAppInactive
  public static bool GetHideWhenAppInactive(DependencyObject obj) { return (bool)obj.GetValue(HideWhenAppInactiveProperty); }
  public static void SetHideWhenAppInactive(DependencyObject obj, bool value) { obj.SetValue(HideWhenAppInactiveProperty, value); }
  public static readonly DependencyProperty HideWhenAppInactiveProperty = DependencyProperty.RegisterAttached("HideWhenAppInactive", typeof(bool), typeof(PopupWindowControl), new PropertyMetadata
    {
      PropertyChangedCallback = (obj, e) =>
        {
          if((bool)e.NewValue && obj is Popup)
          {
            if((_cleanupCounter++ % 10000) == 0)
              _hideWhenInactivePopups = (from weakRef in _hideWhenInactivePopups where weakRef.IsAlive select weakRef).ToList();

            _hideWhenInactivePopups.Add(new WeakReference(obj));
          }
        }
    });

  // AttachHandler
  public static bool GetAttachHandler(DependencyObject obj) { return (bool)obj.GetValue(AttachHandlerProperty); }
  public static void SetAttachHandler(DependencyObject obj, bool value) { obj.SetValue(AttachHandlerProperty, value); }
  public static readonly DependencyProperty AttachHandlerProperty = DependencyProperty.RegisterAttached("AttachHandler", typeof(bool), typeof(PopupWindowControl), new PropertyMetadata
  {
    PropertyChangedCallback = (obj, e) =>
    {
      if((bool)e.NewValue)
      {
        var window = (Window)obj;
        window.Activated += Update;
        window.Deactivated += Update;
        window.StateChanged += Update;
      }
    }
  });

  private static void Update(object sender, EventArgs e)
  {
    var active =
      Application.Current.Windows.OfType<Window>().Where(win =>
        win.IsActive &&
        win.Visibility==Visibility.Visible &&
        win.WindowState != WindowState.Minimized)
        .Any();

    // First update Windows marked HideWhenAppInactive
    foreach(var popupWindow in Application.Current.Windows.OfType<Window>().Where(win => GetHideWhenAppInactive(win)))
      popupWindow.Visibility = active ? Visibility.Visible : Visibility.Hidden;

    // Then update Popups marked HideWhenAppInactive
    if(active && _temporarilyHiddenPopups!=null)
    {
      foreach(var popup in _temporarilyHiddenPopups)
        popup.IsOpen = true;
      _temporarilyHiddenPopups = null;
    }
    else if(!active)
    {
      if(_temporarilyHiddenPopups==null) _temporarilyHiddenPopups = new List<Popup>();
      foreach(var popup in
        (from weak in _hideWhenInactivePopups 
         let popup = weak.Target as Popup
         where popup!=null && popup.IsOpen && GetHideWhenAppInactive(popup)
         select popup))
      {
        _temporarilyHiddenPopups.Add(popup);
        popup.IsOpen = false;
      }
    }
  }

  private static List<WeakReference> _hideWhenInactivePopups = new List<WeakReference>();
  private static List<Popup> _temporarilyHiddenPopups;
  private static int _cleanupCounter;
}

请注意，当"AttachHandler“或"HideWhenAppInactive”设置为false时，我没有添加任何代码来分离处理程序，因为为此目的，它们永远不会以这种方式使用。