Winform 中的KeyDown

 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
 using System.Drawing;
 using System.Linq;
 using System.Text;
 using System.Windows.Forms;
 using System.Xml;
 using System.Runtime.InteropServices;

 namespace WindowsFormsApplication1
 {
     public partial class Main : Form
     {
         public Main()
         {
             this.KeyPreview = true;
             InitializeComponent();
             //TopMost = true;
             LoadMax();
         }

         private void picXS_Click(object sender, EventArgs e)
         {
             Form1 form = new Form1();
             this.Hide();
             form.Show();
         }

         private void pictureBox1_Click(object sender, EventArgs e)
         {
             if (MessageBox.Show("确认注销吗？", "请确认", MessageBoxButtons.YesNo) == DialogResult.Yes)
             {

                 Login login = new Login();
                 this.Hide();
                 login.Show();
             }
         }

         private void pictureBox2_Click(object sender, EventArgs e)
         {
             SelectShowInfo select = new SelectShowInfo();
             this.Hide();
             select.Show();
         }

         private void pictureBox3_Click(object sender, EventArgs e)
         {

             SubInfo info = new SubInfo();
             this.Hide();
             info.Show();

         }

         private void Main_Load(object sender, EventArgs e)
         {

         }

         public void LoadMax()
         {
             if (this.WindowState == FormWindowState.Maximized)
             {
                 this.WindowState = FormWindowState.Normal;
             }
             else
             {
                 this.FormBorderStyle = FormBorderStyle.None;
                 this.WindowState = FormWindowState.Maximized;
             }
         }

         private void pictureBox5_Click(object sender, EventArgs e)
         {
             SubSummary subsum = new SubSummary();
             this.Hide();
             subsum.Show();
         }

         private void Form1_KeyDown(object sender, KeyEventArgs e)
         {

         }

         private void Main_KeyDown(object sender, KeyEventArgs e)
         {
             if (e.KeyCode == Keys.F7)
             {
                 WEB main = new WEB();
                 this.Hide();

                 main.Show();
             }

             if (e.KeyCode == Keys.NumPad1)
             {
                 picXS_Click(sender, e);

             }

             if (e.KeyCode == Keys.NumPad2)
             {
                 pictureBox2_Click(sender, e);

             }

             if (e.KeyCode == Keys.NumPad3)
             {
                 pictureBox5_Click(sender, e);

             }

             if (e.KeyCode == Keys.NumPad4)
             {
                 pictureBox3_Click(sender, e);

             }

             if (e.KeyCode == Keys.NumPad5)
             {
                 pictureBox1_Click(sender, e);

             }

             if (e.KeyCode == Keys.NumPad6) {
                 picBminPwd_Click(sender,e);
             }

             //禁止相关快捷键
             if (e.Modifiers == Keys.Alt
                 || e.Modifiers == Keys.LWin
                 || e.Modifiers == Keys.RWin
               )
             {
               e.Handled = true;
             }

             //弹出Password窗体
             //if (e.Alt == true)
             //{
             //  PassWords password = new PassWords();
             //  e.Handled = false;
             //  password.Show();
             //}
         }

         private void picBminPwd_Click(object sender, EventArgs e)
         {

             PassWords pwd = new PassWords();
             pwd.ShowDialog();

         }

         ////倒计时
         //[StructLayout(LayoutKind.Sequential)]

         //struct LASTINPUTINFO
         //{
         //  [MarshalAs(UnmanagedType.U4)]
         //  public int cbSize;

         //  [MarshalAs(UnmanagedType.U4)]
         //  public uint dwTime;
         //}

         //[DllImport("user32.dll")]

         //static extern bool GetLastInputInfo(ref LASTINPUTINFO plii);

         //static long GetLastInputTime()
         //{
         //  LASTINPUTINFO vLastInputInfo = new LASTINPUTINFO();
         //  vLastInputInfo.cbSize = Marshal.SizeOf(vLastInputInfo);

         //  if (!GetLastInputInfo(ref vLastInputInfo))

         //    return 0;

         //  return Environment.TickCount - (long)vLastInputInfo.dwTime;
         //}

         //private void timer1_Tick(object sender, EventArgs e)
         //{
         //  if (GetLastInputTime() > 3000)
         //  {
         //    timer1.Stop();

         //    Screen screen = new Screen();

         //    this.Hide();

         //    screen.Show();
         //  }
         //}

     }
 }