/// <summary>
        /// Calls the Win32 SendInput method with a stream of KeyDown and KeyUp messages in order to simulate uninterrupted text entry via the keyboard.
        /// </summary>
        /// <param name="text">The text to be simulated.</param>
        public static void SimulateTextEntry(string text)
        {
            if (text.Length > UInt32.MaxValue / 2) throw new ArgumentException(string.Format("The text parameter is too long. It must be less than {0} characters.", UInt32.MaxValue / 2), "text");

            var chars = UTF8Encoding.ASCII.GetBytes(text);
            var len = chars.Length;
            INPUT[] inputList = new INPUT[len * 2];
            for (int x = 0; x < len; x++)
            {
                UInt16 scanCode = chars[x];

                var down = new INPUT();
                down.Type = (UInt32)InputType.KEYBOARD;
                down.Data.Keyboard = new KEYBDINPUT();
                down.Data.Keyboard.Vk = 0;
                down.Data.Keyboard.Scan = scanCode;
                down.Data.Keyboard.Flags = (UInt32)KeyboardFlag.UNICODE;
                down.Data.Keyboard.Time = 0;
                down.Data.Keyboard.ExtraInfo = IntPtr.Zero;

                var up = new INPUT();
                up.Type = (UInt32)InputType.KEYBOARD;
                up.Data.Keyboard = new KEYBDINPUT();
                up.Data.Keyboard.Vk = 0;
                up.Data.Keyboard.Scan = scanCode;
                up.Data.Keyboard.Flags = (UInt32)(KeyboardFlag.KEYUP | KeyboardFlag.UNICODE);
                up.Data.Keyboard.Time = 0;
                up.Data.Keyboard.ExtraInfo = IntPtr.Zero;

                // Handle extended keys:
                // If the scan code is preceded by a prefix byte that has the value 0xE0 (224),
                // we need to include the KEYEVENTF_EXTENDEDKEY flag in the Flags property.
                if ((scanCode & 0xFF00) == 0xE000)
                {
                    down.Data.Keyboard.Flags |= (UInt32)KeyboardFlag.EXTENDEDKEY;
                    up.Data.Keyboard.Flags |= (UInt32)KeyboardFlag.EXTENDEDKEY;
                }

                inputList[2*x] = down;
                inputList[2*x + 1] = up;

            }

            var numberOfSuccessfulSimulatedInputs = SendInput((UInt32)len*2, inputList, Marshal.SizeOf(typeof(INPUT)));
        }
 static extern UInt32 SendInput(UInt32 numberOfInputs, INPUT[] inputs, Int32 sizeOfInputStructure);
        /// <summary>
        /// Calls the Win32 SendInput method to simulate a Key UP.
        /// </summary>
        /// <param name="keyCode">The VirtualKeyCode to lift up</param>
        public static void SimulateKeyUp(VirtualKeyCode keyCode)
        {
            var up = new INPUT();
            up.Type = (UInt32)InputType.KEYBOARD;
            up.Data.Keyboard = new KEYBDINPUT();
            up.Data.Keyboard.Vk = (UInt16)keyCode;
            up.Data.Keyboard.Scan = 0;
            up.Data.Keyboard.Flags = (UInt32)KeyboardFlag.KEYUP;
            up.Data.Keyboard.Time = 0;
            up.Data.Keyboard.ExtraInfo = IntPtr.Zero;

            INPUT[] inputList = new INPUT[1];
            inputList[0] = up;

            var numberOfSuccessfulSimulatedInputs = SendInput(1, inputList, Marshal.SizeOf(typeof(INPUT)));
            if (numberOfSuccessfulSimulatedInputs == 0) throw new Exception(string.Format("The key up simulation for {0} was not successful.", keyCode));
        }