using System.Windows.Forms;

namespace KeysExchange

{

    partial class Form1

    {

        /// <summary>

        /// Required designer variable.

        /// </summary>

        private System.ComponentModel.IContainer components = null;

        /// <summary>

        /// Clean up any resources being used.

        /// </summary>

        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>

        protected override void Dispose(bool disposing)

        {

            if (disposing && (components != null))

            {

                components.Dispose();

            }

            base.Dispose(disposing);

        }

        #region Windows Form Designer generated code

        /// <summary>

        /// Required method for Designer support - do not modify

        /// the contents of this method with the code editor.

        /// </summary>

        private void InitializeComponent()

        {

            this.intall_button = new System.Windows.Forms.Button();

            this.uninstall_button = new System.Windows.Forms.Button();

            this.comboBox1 = new System.Windows.Forms.ComboBox();

            this.comboBox2 = new System.Windows.Forms.ComboBox();

            this.label1 = new System.Windows.Forms.Label();

            this.SuspendLayout();

            //

            // intall_button

            //

            this.intall_button.Location = new System.Drawing.Point(, );

            this.intall_button.Name = "intall_button";

            this.intall_button.Size = new System.Drawing.Size(, );

            this.intall_button.TabIndex = ;

            this.intall_button.Text = "Install";

            this.intall_button.UseVisualStyleBackColor = true;

            this.intall_button.Click += new System.EventHandler(this.intall_button_Click);

            //

            // uninstall_button

            //

            this.uninstall_button.Location = new System.Drawing.Point(, );

            this.uninstall_button.Name = "uninstall_button";

            this.uninstall_button.Size = new System.Drawing.Size(, );

            this.uninstall_button.TabIndex = ;

            this.uninstall_button.Text = "Uninstall";

            this.uninstall_button.UseVisualStyleBackColor = true;

            this.uninstall_button.Click += new System.EventHandler(this.uninstall_button_Click);

            //

            // comboBox1

            //

            this.comboBox1.FormattingEnabled = true;

            this.comboBox1.Location = new System.Drawing.Point(, );

            this.comboBox1.Name = "comboBox1";

            this.comboBox1.Size = new System.Drawing.Size(, );

            this.comboBox1.TabIndex = ;

            this.comboBox1.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;

            //

            // comboBox2

            //

            this.comboBox2.FormattingEnabled = true;

            this.comboBox2.Location = new System.Drawing.Point(, );

            this.comboBox2.Name = "comboBox2";

            this.comboBox2.Size = new System.Drawing.Size(, );

            this.comboBox2.TabIndex = ;

            this.comboBox2.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;

            //

            // label1

            //

            this.label1.AutoSize = true;

            this.label1.Location = new System.Drawing.Point(, );

            this.label1.Name = "label1";

            this.label1.Size = new System.Drawing.Size(, );

            this.label1.TabIndex = ;

            this.label1.Text = "改为：";

            //

            // Form1

            //

            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);

            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;

            this.ClientSize = new System.Drawing.Size(, );

            this.Controls.Add(this.label1);

            this.Controls.Add(this.comboBox2);

            this.Controls.Add(this.comboBox1);

            this.Controls.Add(this.uninstall_button);

            this.Controls.Add(this.intall_button);

            this.Name = "Form1";

            this.Text = "KeysExchange";

            this.ResumeLayout(false);

            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.Button intall_button;

        private System.Windows.Forms.Button uninstall_button;

        private System.Windows.Forms.ComboBox comboBox1;

        private System.Windows.Forms.ComboBox comboBox2;

        private System.Windows.Forms.Label label1;

    }

    struct ComboItem

    {

        private string text;

        private string value;

        public ComboItem(string text, string value)

        {

            this.text = text;

            this.value = value;

        }

        public override string ToString()

        {

            return this.text;

        }

        public string ToValue()

        {

            return this.value;

        }

    }

}

using System;

using System.Diagnostics;

using System.Runtime.InteropServices;

namespace KeysExchange

{

    public class KeyboardHookLib

    {

        private const int WH_KEYBOARD_LL = ;

        private delegate int HookHandle(int nCode, int wParam, IntPtr lParam);

        public delegate void ProcessKeyHandle(HookStruct param, out bool handle);

        private static int _hHookValue = ;

        private HookHandle _KeyBoardHookProcedure;

        [StructLayout(LayoutKind.Sequential)]

        public class HookStruct

        {

            public int vkCode;

            public int scanCode;

            public int flags;

            public int time;

            public int dwExtraInfo;

        }

        [DllImport("user32.dll")]

        private static extern int SetWindowsHookEx(int idHook, HookHandle lpfn, IntPtr hInstance, int threadId);

        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]

        private static extern bool UnhookWindowsHookEx(int idHook);

        [DllImport("user32.dll")]

        private static extern int CallNextHookEx(int idHook, int nCode, int wParam, IntPtr lParam);

        [DllImport("kernel32.dll")]

        private static extern int GetCurrentThreadId();

        [DllImport("kernel32.dll")]

        private static extern IntPtr GetModuleHandle(string name);

        private IntPtr _hookWindowPtr = IntPtr.Zero;

        public KeyboardHookLib() { }

        private static ProcessKeyHandle _clientMethod = null;

        [DllImport("user32")]

        public static extern int GetKeyboardState(byte[] pbKeyState);

        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]

        private static extern short GetKeyState(int vKey);

        private const int WM_KEYDOWN = 0x100;//KEYDOWN

        private const int WM_KEYUP = 0x101;//KEYUP

        private const int WM_SYSKEYDOWN = 0x104;//SYSKEYDOWN

        private const int WM_SYSKEYUP = 0x105;//SYSKEYUP

        public void InstallHook(ProcessKeyHandle clientMethod)

        {

            _clientMethod = clientMethod;

            if (_hHookValue == )

            {

                _KeyBoardHookProcedure = new HookHandle(OnHookProc);

                _hookWindowPtr = GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName);

                _hHookValue = SetWindowsHookEx(WH_KEYBOARD_LL, _KeyBoardHookProcedure, _hookWindowPtr, );

                if (_hHookValue == ) UninstallHook();

            }

        }

        public void UninstallHook()

        {

            if (_hHookValue != )

            {

                if (UnhookWindowsHookEx(_hHookValue))

                {

                    _hHookValue = ;

                }

            }

        }

        private static int OnHookProc(int nCode, int wParam, IntPtr lParam)

        {

            if (nCode >= )

            {

                HookStruct hookStruct = (HookStruct)Marshal.PtrToStructure(lParam, typeof(HookStruct));

                if (_clientMethod != null)

                {

                    bool handle = false;

                    ///Tylan: Judge if the event is KeyDown or not.

                    if (lParam.ToInt32() >  && wParam == 0x100)

                    {

                        _clientMethod(hookStruct, out handle);

                    }

                    if (handle) return ;

                }

            }

            return CallNextHookEx(_hHookValue, nCode, wParam, lParam);

        }

    }

}

using System;

using System.Windows.Forms;

namespace KeysExchange

{

    public partial class Form1 : Form

    {

        private KeyboardHookLib _keyboardHook = null;

        public Form1()

        {

            InitializeComponent();

            for (int alp = ; alp <= ; alp++)

            {

                ComboItem item = new ComboItem(((Keys)alp).ToString(), alp.ToString());

                comboBox1.Items.Add(item);

                comboBox2.Items.Add(item);

            }

        }

        private void intall_button_Click(object sender, EventArgs e)

        {

            //Install the hook.

            _keyboardHook = new KeyboardHookLib();

            _keyboardHook.InstallHook(this.OnKeyPress);

        }

        private void uninstall_button_Click(object sender, EventArgs e)

        {

            //Cancel the hook.

            if (_keyboardHook != null) _keyboardHook.UninstallHook();

        }

        public void OnKeyPress(KeyboardHookLib.HookStruct hookStruct, out bool handle)

        {

            handle = false;

            if (((Keys)hookStruct.vkCode).ToString() == comboBox1.SelectedItem.ToString())

            {

                handle = true;

                //Exchange the keys.

                hookStruct.vkCode = int.Parse(((ComboItem)comboBox2.SelectedItem).ToValue());

                Keys key = (Keys)hookStruct.vkCode;

                //MessageBox.Show((key == Keys.None ? "" : key.ToString()));

                System.Windows.Forms.SendKeys.Send(key.ToString().ToLower());

            }

        }

    }

}