crescent

я использую свой класс

public class MouseSimulator
    {
        public static void ClickLeftMouseButton()
        {
            INPUT mouseDownInput = new INPUT();
            mouseDownInput.type = SendInputEventType.InputMouse;
            mouseDownInput.mkhi.mi.dwFlags = MouseEventFlags.MOUSEEVENT_LEFTDOWN;
            User32.SendInput(1, ref mouseDownInput, Marshal.SizeOf(new INPUT()));

            INPUT mouseUpInput = new INPUT();
            mouseUpInput.type = SendInputEventType.InputMouse;
            mouseUpInput.mkhi.mi.dwFlags = MouseEventFlags.MOUSEEVENT_LEFTUP;
            User32.SendInput(1, ref mouseUpInput, Marshal.SizeOf(new INPUT()));
        }
        public static void ClickRightMouseButton()
        {
            INPUT mouseDownInput = new INPUT();
            mouseDownInput.type = SendInputEventType.InputMouse;
            mouseDownInput.mkhi.mi.dwFlags = MouseEventFlags.MOUSEEVENT_RIGHTDOWN;
            User32.SendInput(1, ref mouseDownInput, Marshal.SizeOf(new INPUT()));

            INPUT mouseUpInput = new INPUT();
            mouseUpInput.type = SendInputEventType.InputMouse;
            mouseUpInput.mkhi.mi.dwFlags = MouseEventFlags.MOUSEEVENT_RIGHTUP;
            User32.SendInput(1, ref mouseUpInput, Marshal.SizeOf(new INPUT()));
        }

        public static void MouseMove(int dx, int dy)
        {
            INPUT mouseMove = new INPUT();
            mouseMove.type = SendInputEventType.InputMouse;
            mouseMove.mkhi.mi.dwFlags = MouseEventFlags.MOUSEEVENT_ABSOLUTE | MouseEventFlags.MOUSEEVENT_MOVE;
            mouseMove.mkhi.mi.dx = dx;
            mouseMove.mkhi.mi.dy = dy;
            User32.SendInput(1, ref mouseMove, Marshal.SizeOf(new INPUT()));
        }

        public static void LinearSmoothMove(Point newPosition, TimeSpan duration)
        {
            var point = MouseOperations.GetCursorPosition();
            Point start = new Point(point.X, point.Y);

            // Find the vector between start and newPosition
            double deltaX = newPosition.X - start.X;
            double deltaY = newPosition.Y - start.Y;

            // start a timer
            Stopwatch stopwatch = new Stopwatch();
            stopwatch.Start();

            double timeFraction = 0.0;

            do
            {
                timeFraction = (double)stopwatch.Elapsed.Ticks / duration.Ticks;
                if (timeFraction > 1.0)
                    timeFraction = 1.0;

                PointF curPoint = new PointF(Convert.ToInt32(start.X + timeFraction * deltaX),
                    Convert.ToInt32(start.Y + timeFraction * deltaY));

                //MouseOperations.SetCursorPos(Convert.ToInt32(curPoint.X), Convert.ToInt32(curPoint.Y));
                //MouseSimulator.MouseMove(Convert.ToInt32(curPoint.X), Convert.ToInt32(curPoint.Y));
                int inputXinPixels = Convert.ToInt32(curPoint.X);
                int inputYinPixels = Convert.ToInt32(curPoint.Y);
                var screenBounds = Screen.PrimaryScreen.Bounds;
                var outputX = inputXinPixels * 65535 / screenBounds.Width;
                var outputY = inputYinPixels * 65535 / screenBounds.Height;
                //Console.WriteLine(outputX);
                MouseSimulator.MouseMove(outputX, outputY);
                Thread.Sleep(50);
            } while (timeFraction < 1.0);
        }
    }



    [StructLayout(LayoutKind.Sequential)]
    public struct POINT
    {
        public int x;
        public int y;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct INPUT
    {
        public SendInputEventType type;
        public MOUSEANDKEYBOARDINPUT mkhi;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct KEYBOARDINPUT
    {
        public ushort wVk;
        public ushort wScan;
        public uint dwFlags;
        public uint time;
        public IntPtr dwExtraInfo;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct HARDWAREINPUT
    {
        public int uMsg;
        public short wParamL;
        public short wParamH;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct MOUSEINPUT
    {
        public int dx;
        public int dy;
        public uint mouseData;
        public MouseEventFlags dwFlags;
        public uint time;
        public IntPtr dwExtraInfo;
    }

    [StructLayout(LayoutKind.Explicit)]
    public struct MOUSEANDKEYBOARDINPUT
    {
        [FieldOffset(0)]
        public MOUSEINPUT mi;

        [FieldOffset(0)]
        public KEYBOARDINPUT ki;

        [FieldOffset(0)]
        public HARDWAREINPUT hi;
    }

    [Flags]
    public enum MouseEventFlags : uint
    {
        MOUSEEVENT_MOVE = 0x0001,
        MOUSEEVENT_LEFTDOWN = 0x0002,
        MOUSEEVENT_LEFTUP = 0x0004,
        MOUSEEVENT_RIGHTDOWN = 0x0008,
        MOUSEEVENT_RIGHTUP = 0x0010,
        MOUSEEVENT_MIDDLEDOWN = 0x0020,
        MOUSEEVENT_MIDDLEUP = 0x0040,
        MOUSEEVENT_XDOWN = 0x0080,
        MOUSEEVENT_XUP = 0x0100,
        MOUSEEVENT_WHEEL = 0x0800,
        MOUSEEVENT_VIRTUALDESK = 0x4000,
        MOUSEEVENT_ABSOLUTE = 0x8000
    }

    [Flags]
    public enum SendInputEventType : uint
    {
        InputMouse,
        InputKeyboard,
        InputHardware
    }

    public class User32
    {
        [DllImport("user32.dll")]
        public static extern long SetCursorPos(int x, int y);

        [DllImport("user32.dll")]
        public static extern bool ClientToScreen(IntPtr hWnd, ref POINT point);

        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool GetCursorPos(out POINT p);

        [DllImport("user32.dll", SetLastError = true)]
        public static extern uint SendInput(uint nInputs, ref INPUT pInputs, int cbSize);

        [DllImport("user32.dll")]
        public static extern IntPtr GetDesktopWindow();

        [DllImport("user32.dll")]
        public static extern IntPtr GetWindowDC(IntPtr ptr);
    }

собственно чтобы кликнуть надо:
LinearSmoothMove(Point newPosition, TimeSpan duration)
ClickLeftMouseButton()

я его использую что в вк куче народу писать) работает хорошо