.NET：如何检查鼠标是否在控件中？

Question

我想知道鼠标是否在 .NET 中的特定控件中

private void panel1_MouseLeave(object sender, EventArgs e)
{
   if (MouseIsInControl((Control)sender)
      return; //the mouse didn't leave, don't fire a MouseLeave event

   ...
}

public Boolean MouseIsInControl(Control control)
{
    //return (control.Bounds.Contains(MousePosition));
    return control.Bounds.Contains(control.PointToClient(MousePosition))
}

但我需要有人摆弄四个不同的坐标系才能使其工作.

相关问题

• How to detect if the mouse is inside the whole form and child controls in C#?（整个表格）
• Custom controls in C# Windows Forms mouse event question（内部带有标签的控件）

Answer 1

不需要挂钩或子类化。

private bool MouseIsOverControl(Button btn) => 
    btn.ClientRectangle.Contains(btn.PointToClient(Cursor.Position))

如果鼠标位于包含控件的表单之外，此方法也可以使用。它使用按钮对象，但您可以使用任何 UI 类

您可以像这样轻松测试该方法：

private void button1_Click(object sender, EventArgs e)
{
    // Sleep to allow you time to move the mouse off the button
    System.Threading.Thread.Sleep(900); 

    // Try moving mouse around or keeping it over the button for different results
    if (MouseIsOverControl(button1))
         MessageBox.Show("Mouse is over the button.");
    else MessageBox.Show("Mouse is NOT over the button.");
}

Answer 2

这个Hans Passant Answer可以适应你想要的：

private bool mEntered;
private Timer timer1;

public Form1() {
  InitializeComponent();

  timer1 = new Timer();
  timer1.Interval = 200;
  timer1.Tick += timer1_Tick;
  timer1.Enabled = false;
}

private void panel1_MouseEnter(object sender, EventArgs e) {
  timer1.Enabled = true;
}

private void timer1_Tick(object sender, EventArgs e) {
  bool entered = panel1.ClientRectangle.Contains(panel1.PointToClient(Cursor.Position));
  if (entered != mEntered) {
    mEntered = entered;
    if (!entered) {
      timer1.Enabled = false;
      // OK, Do something, the mouse left the parent container
    }
  }
}

Answer 3

我也为此解决方案使用 System.Windows.Forms.Timer，但我不再使用进入/离开鼠标事件。他们给我带来了太多的悲伤。相反，我在我需要知道鼠标已结束的组件上使用 MouseMove 事件。我在这个类中有 2 个成员变量。

bool Hovering = false;
System.Drawing.Point LastKnownMousePoint = new System.Drawing.Point();

就我而言，我想切换标签周围的边框。我处理知道鼠标是否在我关心的标签控件上如下：

    private void label1_MouseMove(object sender, MouseEventArgs e)
    {
        // Mouse Position relative to the form... not the control
        LastKnownMousePoint = Cursor.Position; 

        label1.BorderStyle = BorderStyle.Fixed3D;
        timer1.Stop();
        timer1.Interval = 50; // Very fast (Overkill?  :) )
        timer1.Start();
    }

    private void timer1_Tick(object sender, EventArgs e)
    {
        System.Drawing.Point point = Cursor.Position;
        if (LastKnownMousePoint.Equals(point))
        {
            // If the mouse is somewhere on the label, I'll call that Hovering.  
            // Though not technically the MS definition, it works for me.
            Hovering = true;
        }
        else if (Hovering == false)
        {
            label1.BorderStyle = BorderStyle.None;
            timer1.Stop();
        }
        else
        {
            Hovering = false;
            // Next time the timer ticks, I'll stop the timer and
            // Toggle the border.
        }
    }

这是因为我只在鼠标悬停在控件上时才更新 LastKnownMousePoint（本例中为标签）。因此，如果鼠标移出控件，我将不会更新 LastKnownMousePoint，我会知道是时候切换边框样式了。