//using System;
//using System.Runtime.InteropServices;
//using System.Windows.Forms;

private const int INPUT_MOUSE = 0;
private const uint MOUSEEVENTF_MOVE = 0x0001U;
private const uint MOUSEEVENTF_LEFTDOWN = 0x0002U;
private const uint MOUSEEVENTF_LEFTUP = 0x0004U;
private const uint MOUSEEVENTF_RIGHTDOWN = 0x0008U;
private const uint MOUSEEVENTF_RIGHTUP = 0x0010U;
private const uint MOUSEEVENTF_MIDDLEDOWN = 0x0020U;
private const uint MOUSEEVENTF_MIDDLEUP = 0x0040U;
private const uint MOUSEEVENTF_XDOWN = 0x0080U;
private const uint MOUSEEVENTF_XUP = 0x0100U;
private const uint MOUSEEVENTF_WHEEL = 0x0800U;
private const uint MOUSEEVENTF_HWHEEL = 0x01000U;
private const uint MOUSEEVENTF_ABSOLUTE = 0x8000U;
private const int XBUTTON1 = 0x0001;
private const int XBUTTON2 = 0x0002;
private const int WHEEL_DELTA = 120;

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

[StructLayout(LayoutKind.Explicit)]
private struct INPUT {
  [FieldOffset(0)]
  public uint type;
  [FieldOffset(4)]
  public MOUSEINPUT mi;
};

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

public static uint MouseEvent(int dx, int dy, int mouseData, uint dwFlags, uint time, IntPtr dwExtraInfo) {
  INPUT mInput = new INPUT();
  mInput.type = INPUT_MOUSE;
  mInput.mi = new MOUSEINPUT();
  mInput.mi.dx = dx;
  mInput.mi.dy = dy;
  mInput.mi.mouseData = mouseData;
  mInput.mi.dwFlags = dwFlags;
  mInput.mi.time = time;
  mInput.mi.dwExtraInfo = dwExtraInfo;
  return SendInput(1U, ref mInput, Marshal.SizeOf(mInput));
}
public static uint MouseMove(int dx, int dy) {
  return MouseEvent(dx * 65535 / Screen.PrimaryScreen.Bounds.Width, dy * 65535 / Screen.PrimaryScreen.Bounds.Height, 0, MOUSEEVENTF_ABSOLUTE | MOUSEEVENTF_MOVE, 0U, IntPtr.Zero);
}
public static uint MouseButtonDown(MouseButtons Button) {
  switch (Button) {
    case MouseButtons.Left:
      return MouseEvent(0, 0, 0, MOUSEEVENTF_LEFTDOWN, 0U, IntPtr.Zero);
    case MouseButtons.Middle:
      return MouseEvent(0, 0, 0, MOUSEEVENTF_MIDDLEDOWN, 0U, IntPtr.Zero);
    case MouseButtons.Right:
      return MouseEvent(0, 0, 0, MOUSEEVENTF_RIGHTDOWN, 0U, IntPtr.Zero);
    case MouseButtons.XButton1:
      return MouseEvent(0, 0, XBUTTON1, MOUSEEVENTF_XDOWN, 0U, IntPtr.Zero);
    case MouseButtons.XButton2:
      return MouseEvent(0, 0, XBUTTON2, MOUSEEVENTF_XDOWN, 0U, IntPtr.Zero);
    default:
      return 0;
  }
}
public static uint MouseButtonDown(MouseButtons Button, int dx, int dy) {
  return MouseMove(dx, dy) + MouseButtonDown(Button);
}
public static uint MouseButtonUp(MouseButtons Button) {
  switch (Button) {
    case MouseButtons.Left:
      return MouseEvent(0, 0, 0, MOUSEEVENTF_LEFTUP, 0U, IntPtr.Zero);
    case MouseButtons.Middle:
      return MouseEvent(0, 0, 0, MOUSEEVENTF_MIDDLEUP, 0U, IntPtr.Zero);
    case MouseButtons.Right:
      return MouseEvent(0, 0, 0, MOUSEEVENTF_RIGHTUP, 0U, IntPtr.Zero);
    case MouseButtons.XButton1:
      return MouseEvent(0, 0, XBUTTON1, MOUSEEVENTF_XUP, 0U, IntPtr.Zero);
    case MouseButtons.XButton2:
      return MouseEvent(0, 0, XBUTTON2, MOUSEEVENTF_XUP, 0U, IntPtr.Zero);
    default:
      return 0;
  }
}
public static uint MouseButtonUp(MouseButtons Button, int dx, int dy) {
  return MouseMove(dx, dy) + MouseButtonUp(Button);
}
public static uint MouseButtonClick(MouseButtons Button) {
  return MouseButtonDown(Button) + MouseButtonUp(Button);
}
public static uint MouseButtonClick(MouseButtons Button, int dx, int dy) {
  return MouseMove(dx, dy) + MouseButtonDown(Button) + MouseButtonUp(Button);
}
public static uint MouseWheel(int Count) {
  return MouseEvent(0, 0, (int)(WHEEL_DELTA * Count), MOUSEEVENTF_WHEEL, 0U, IntPtr.Zero);
}
public static uint MouseHWheel(int Count) {
  return MouseEvent(0, 0, (int)(WHEEL_DELTA * Count), MOUSEEVENTF_HWHEEL, 0U, IntPtr.Zero);
}