鼠标移到控件上显示，移出控件消失

 1 using System;
 2 using System.Collections.Generic;
 3 using System.ComponentModel;
 4 using System.Data;
 5 using System.Drawing;
 6 using System.Text;
 7 using System.Windows.Forms;
 8 
 9 namespace juxing
10 {
11     public partial class Form1 : Form
12     {
13         public Form1()
14         {
15             InitializeComponent();
16         }
17 
18         private void Form1_Load(object sender, EventArgs e)
19         {          
20             button1.Visible = false;
21         }
22 
23         private void Form1_MouseMove(object sender, MouseEventArgs e)
24         {         
25              Point point= this.PointToScreen(new Point(e.X, e.Y));
26              Rectangle rc = this.button1.RectangleToScreen(this.button1.ClientRectangle);
27              if (rc.Contains(point))
28              {
29                  button1.Visible = true;
30              }
31              else
32              {
33                  button1.Visible = false;
34              }           
35         }                 
36     }
37 }