using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;

namespace POSV.Utils
{
    public class InputSimulatorUtils
    {
        const uint KEYEVENTF_EXTENDEDKEY = 0x1;

        const uint KEYEVENTF_KEYUP = 0x2;

        [DllImport("user32.dll")]
        static extern short GetKeyState(int nVirtKey);
        [DllImport("user32.dll")]
        static extern void keybd_event(byte bVk , byte bScan , uint dwFlags , uint dwExtraInfo);
        public enum VirtualKeys : byte
        {
            VK_NUMLOCK = 0x90, //数字锁定键
            VK_SCROLL = 0x91, //滚动锁定
            VK_CAPITAL = 0x14, //大小写锁定
            VK_A = 62
        }

        public static bool GetState(VirtualKeys Key)
        {
            return (GetKeyState((int)Key) == 1);
        }

        public static void SetState(VirtualKeys Key , bool State)
        {
            if (State != GetState(Key))
            {
                keybd_event((byte)Key , 0x45 , KEYEVENTF_EXTENDEDKEY | 0 , 0);
                keybd_event((byte)Key , 0x45 , KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP , 0);
            }
        }

        //开启键盘大写   SetState(VirtualKeys.VK_CAPITAL, true);
        //关闭键盘大写   SetState(VirtualKeys.VK_CAPITAL, false);
        //开启键盘滚动锁定  SetState(VirtualKeys.VK_SCROLL, true);
        //关闭键盘滚动锁定  SetState(VirtualKeys.VK_SCROLL, false);
        //开启键盘数字锁定键  SetState(VirtualKeys.VK_NUMLOCK, true);
        //关闭键盘数字锁定键  SetState(VirtualKeys.VK_NUMLOCK, false);


        public static void SendKey(VirtualKeyCode key)
        {
            keybd_event((byte)key , 0 , KEYEVENTF_EXTENDEDKEY | 0 , 0);//按下
            keybd_event((byte)key , 0 , KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP , 0);//释放
        }

        public const byte vbKeyControl = 0x11;   // CTRL 键
        public const byte vbKeyShift = 0x10;     // SHIFT 键
        public static void SendCtrlShift()
        {
            //模拟按下ctrl键
            keybd_event(vbKeyControl , 0 , 0 , 0);
            //模拟按下shift键
            keybd_event(vbKeyShift , 0 , 0 , 0);
            //松开按键ctrl
            keybd_event(vbKeyControl , 0 , 2 , 0);
            //松开按键shift
            keybd_event(vbKeyShift , 0 , 2 , 0);
        }

        public static void SendClear(int length = 0)
        {
            if (length != 0)
            {
                for (int i = 0; i < length; i++)
                {
                    //模拟按下back键
                    keybd_event((byte)VirtualKeyCode.BACK, 0, 0, 0);
                    //松开按键back键
                    keybd_event((byte)VirtualKeyCode.BACK, 0, 2, 0);
                }
            }
            else
            {
                //模拟按下ctrl键
                keybd_event(vbKeyControl, 0, 0, 0);
                //模拟按下A键
                keybd_event((byte)VirtualKeyCode.VK_A, 0, 0, 0);

                //松开按键ctrl
                keybd_event(vbKeyControl, 0, 2, 0);
                //松开按键A
                keybd_event((byte)VirtualKeyCode.VK_A, 0, 2, 0);

                //模拟按下back键
                keybd_event((byte)VirtualKeyCode.BACK, 0, 0, 0);
                //松开按键back键
                keybd_event((byte)VirtualKeyCode.BACK, 0, 2, 0);
            }

          
        }

    } 
}