如何检测鼠标何时离开表格？

Question

我有一个表格,上面有很多控件.如何检测鼠标何时离开表格？我已尝试为每个控件和表单连接一个MouseLeave事件,但这不起作用,因为当鼠标经过控件时,这些事件会一直触发.有没有一种实际有效的方法.

Answer 1

你应该听:

• MouseLeave窗体的所有控件的事件
• 表单的MouseLeave事件

只需将您的侦听器链接到一个函数,该函数检查光标是否在表单客户端中.

试试这个:

    protected override void OnControlAdded(ControlEventArgs e)
    {
        SubscribeEvents(e.Control);
        base.OnControlAdded(e);
    }

    protected override void OnControlRemoved(ControlEventArgs e)
    {
        UnsubscribeEvents(e.Control);
        base.OnControlRemoved(e);
    }

    private void SubscribeEvents(Control control)
    {
        control.MouseLeave += new EventHandler(control_MouseLeave);
        control.ControlAdded += new ControlEventHandler(control_ControlAdded);
        control.ControlRemoved += new ControlEventHandler(control_ControlRemoved);

        foreach (Control innerControl in control.Controls)
        {
            SubscribeEvents(innerControl);
        }
    }

    private void UnsubscribeEvents(Control control)
    {
        control.MouseLeave -= new EventHandler(control_MouseLeave);
        control.ControlAdded -= new ControlEventHandler(control_ControlAdded);
        control.ControlRemoved -= new ControlEventHandler(control_ControlRemoved);

        foreach (Control innerControl in control.Controls)
        {
            UnsubscribeEvents(innerControl);
        }
    }

    private void control_ControlAdded(object sender, ControlEventArgs e)
    {
        SubscribeEvents(e.Control);
    }

    private void control_ControlRemoved(object sender, ControlEventArgs e)
    {
        UnsubscribeEvents(e.Control);
    }

    protected override void OnMouseLeave(EventArgs e)
    {
        CheckMouseLeave();
        base.OnMouseLeave(e);
    }

    private void control_MouseLeave(object sender, EventArgs e)
    {
        CheckMouseLeave();
    }

    private void CheckMouseLeave()
    {
        Point pt = PointToClient(Cursor.Position);

        if (ClientRectangle.Contains(pt) == false)
        {
            OnMouseLeftFrom();
        }
    }

    private void OnMouseLeftFrom()
    {
        Console.WriteLine("Mouse left the form");
    }

Answer 2

我所知道的唯一可靠的方法是计时器。下面是调整滚动不透明度的示例代码：

  public partial class Form1 : Form {
    Timer timer1 = new Timer();
    public Form1() {
      InitializeComponent();
      this.Opacity = 0.10;
      timer1.Tick += new EventHandler(timer1_Tick);
      timer1.Interval = 200;
      timer1.Enabled = true;
    }

    void timer1_Tick(object sender, EventArgs e) {
      Point pos = Control.MousePosition;
      bool inForm = pos.X >= Left && pos.Y >= Top && pos.X < Right && pos.Y < Bottom;
      this.Opacity = inForm ? 0.99 : 0.10;
    }
  }