释放鼠标捕获并让鼠标单击通过

Question

我有一个类似于弹出窗口或菜单的控件.我想显示它,当用户点击框的边界外时,让它隐藏起来.我已经使用了Mouse.Capture(这个,CaptureMode.SubTree)以及在OnLostMouseCapture中以与Menu/Popup相同的方式重新获取捕获.

当用户在控件的边界外单击时,我在OnPreviewMouseDown中释放鼠标捕获.我没有把e.Handled设置为true.鼠标单击将转到主UI上的其他控件,但不会转到窗口的关闭按钮(红色X).它需要2次点击才能关闭应用.

有没有办法告诉WPF重新启动鼠标点击,或发送重复的鼠标点击事件？

这是我的代码.注意我将其重命名为MainMenuControl - 我没有构建菜单,因此Menu/MenuItem和Popup不是选项.

public class MainMenuControl : Control
    {
        static MainMenuControl()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(MainMenuControl), new FrameworkPropertyMetadata(typeof(MainMenuControl)));
        }

        public MainMenuControl()
        {
            this.Loaded += new RoutedEventHandler(MainMenuControl_Loaded);

            Mouse.AddPreviewMouseDownOutsideCapturedElementHandler(this, OnPreviewMouseDownOutsideCapturedElementHandler);
        }

        void MainMenuControl_Loaded(object sender, RoutedEventArgs e)
        {
            this.IsVisibleChanged += new DependencyPropertyChangedEventHandler(MainMenuControl_IsVisibleChanged);
        }

        void MainMenuControl_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            if (this.IsVisible)
            {
                Mouse.Capture(this, CaptureMode.SubTree);
                Debug.WriteLine("Mouse.Capture");
            }
        }

        // I was doing this in OnPreviewMouseDown, but changing to this didn't have any effect
        private void OnPreviewMouseDownOutsideCapturedElementHandler(object sender, MouseButtonEventArgs e)
        {
            Debug.WriteLine("OnPreviewMouseDownOutsideCapturedElementHandler");

            if (!this.IsMouseInBounds())
            {
                if (Mouse.Captured == this)
                {
                    Mouse.Capture(this, CaptureMode.None);
                    Debug.WriteLine("Mouse.Capture released");
                }
                Debug.WriteLine("Close Menu");
            }
        }

        protected override void OnLostMouseCapture(MouseEventArgs e)
        {
            base.OnLostMouseCapture(e);

            Debug.WriteLine("OnLostMouseCapture");

            MainMenuControl reference = e.Source as MainMenuControl;
            if (Mouse.Captured != reference)
            {
                if (e.OriginalSource == reference)
                {
                    if ((Mouse.Captured == null) || (!reference.IsAncestorOf(Mouse.Captured as DependencyObject)))
                    {
                        //TODO: Close
                        Debug.WriteLine("Close Menu");
                    }
                }
                // if a child caused use to lose the capture, then recapture.
                else if (reference.IsAncestorOf(e.OriginalSource as DependencyObject))
                {
                    if (Mouse.Captured == null)
                    {
                        Mouse.Capture(reference, CaptureMode.SubTree);
                        Debug.WriteLine("Mouse.Capture");
                        e.Handled = true;
                    }
                }
                else
                {
                    //TODO: Close
                    Debug.WriteLine("Close Menu");
                }
            }

        }

        private bool IsMouseInBounds()
        {
            Point point = Mouse.GetPosition(this);
            Rect bounds = new Rect(0, 0, this.Width, this.Height);

            return bounds.Contains(point);
        }

    }

Answer 1

问题是你正在谈论的鼠标处理是在WPF事件系统和操作系统的一部分之外,所以我们真的在谈论两个完全不同的鼠标消息队列,这些队列在大多数情况下都能很好地交互,但在这些边缘情况下我们看到互操作性并不完美.

您可以尝试生成Win32鼠标消息或向您自己的窗口发送关闭消息,但所有这些方法都是黑客攻击.由于弹出窗口和菜单表现出与您描述的完全相同的症状,因此看起来似乎没有一种简单的方法可以实现您所描述的内容.

相反,我建议您考虑在鼠标离开窗口的北客户区域或其他一些启发式(例如距控件指定距离)时放弃鼠标捕获.我知道这可能并不理想,但如果你想要关闭按钮工作得非常糟糕,这可能是一个令人满意的妥协.