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

namespace TestCompleteUtil
{
    public class KeyboardSimulate
    {
        [DllImport("USER32.DLL", CharSet = CharSet.Unicode)]
        static extern UInt32 SendInput(UInt32 numberOfInputs, INPUT[] input, Int32 sizeOfInputStructure);

        [StructLayout(LayoutKind.Sequential, Size = 24)]
        struct KEYBDINPUT
        {
            public UInt16 Vk;
            public UInt16 Scan;
            public UInt32 Flags;
            public UInt32 Time;
            public UInt32 ExtraInfo;
        }

        [StructLayout(LayoutKind.Explicit)]
        private struct INPUT
        {
            [FieldOffset(0)]
            public int Type;
            [FieldOffset(4)]
            public KEYBDINPUT ki;
        }

        public static void TextInput(string text)
        {
            char[] chars = text.ToCharArray();

            for (int i = 0; i < chars.Length; i++)
            {
                Thread.Sleep(10);
                UInt16 unicode = chars[i];

                INPUT down = new INPUT();
                down.Type = 1; //INPUT_KEYBOARD
                down.ki.Vk = 0;
                down.ki.Scan = unicode;
                down.ki.Time = 0;
                down.ki.Flags = 0x0004; //KEYEVENTF_UNICODE
                down.ki.ExtraInfo = 0;

                INPUT up = new INPUT();
                up.Type = 1; //INPUT_KEYBOARD
                up.ki.Vk = 0;
                up.ki.Scan = unicode;
                up.ki.Time = 0;
                up.ki.Flags = 0x0004; //KEYEVENTF_UNICODE
                up.ki.ExtraInfo = 0;

                INPUT[] input = new INPUT[2];
                input[0] = down;
                input[1] = up;
                SendInput(1, input, Marshal.SizeOf(typeof(INPUT)));
            }
        }
    }
}